Chinese cryptography: The Chinese Nationalist Party and intelligence management, 1927–1949

This paper is the first scholarly attempt to examine the history of Chinese cryptography and the role it played in building the intelligence network of the Chinese Nationalist Party (KMT) from 1927 to 1949. Rather than investigating the institutional structure of intelligence, I focus on Chinese characters, the primary medium that made cryptology and intelligence possible. Given that the Chinese writing system is by nature nonalphabetic and thus noncipherable, how did cryptography work in Chinese? How did the state and its scientists reengineer Chinese characters for the purposes of secret communication? This paper argues that due to the Chinese writing system itself, Chinese cryptography was bound to the use of codebooks rather than ciphers; thus, “codebook management” was central to building intelligence networks in China.     

The evolution of Ghanaian Internet cafés, 2003–2014

Two main perspectives characterize current research on Internet cafés in the developing world. The “inclusionary” perspective represents these public digital spaces as the most important source of connectivity and inclusion for the global population. The “transitional” perspective represents Internet cafés as a dying business whose obituary is long overdue. This study describes a search for two dozen Internet cafés in Ghana, based on establishments first identified in 2003, accompanied by interviews with patrons and café attendants. Our initial exploration supported the transitional prediction that cafés would be shuttered or replaced by traditional businesses. However, an expanded search led us to the conclusion that “walking distance” replacements for all cafés remained available, supporting the inclusionary view. Qualitative interviews revealed the shift of cybers to business services and their continued importance as online spaces for disadvantaged populations.     

The concept of smartness in cyber–physical systems and connection to urban environment

The next-generation systems are expected to be largely cyber–physical systems (CPSs) that autonomously control physical processes, through sensors and actuators typically in real-time feedback and cooperative control loops distributed among physical and cyber environments. The rapid technological advancements enhance the smartness of these CPSs, pushing their boundaries of performance and efficiency by embedding new information and communication technologies. However, to what extent CPSs should be smarter so that they do not compromise safety and security of safety critical systems? is an open research question. Towards this goal, the purpose of this study is to establish a grounded theory to analyse what makes these systems smart? and eventually, how to find a balance between smartness and safety risks? In this precinct, this article aims to develop a conceptual framework, define the dimensions and derive the characteristics that make CPSs smart. The proposed approach combines an automated informetric and systematic analysis of literature pertinent to the topic of smartness across anthropology, science, engineering and technology. The analysis of a case study building and the discussions presented herein support the connection between the existing understanding of CPSs and smartness offered by the building design approach in urban environment.     

The Talk of Norway: a richly annotated corpus of the Norwegian parliament, 1998–2016

In this work we present the Talk of Norway (ToN) data set, a collection of Norwegian Parliament speeches from 1998 to 2016. Every speech is richly annotated with metadata harvested from different sources, and augmented with language type, sentence, token, lemma, part-of-speech, and morphological feature annotations. We also present a pilot study on party classification in the Norwegian Parliament, carried out in the context of a cross-faculty collaboration involving researchers from both Political Science and Computer Science. Our initial experiments demonstrate how the linguistic and institutional annotations in ToN can be used to gather insights on how different aspects of the political process affect classification.     

Analysis on the variations of atmospheric CO2 concentrations along the urban–rural gradients of Chinese cities based on the OCO-2 XCO2 data

Anthropogenic CO₂ emissions contribute the most to the growth of atmospheric CO₂ concentrations. These emissions are largely concentrated in urban areas where human activities are intense. Studies have been conducted to explore the urban and rural difference in CO₂ concentrations based on ground-based measurements. The launch of NASA’s Orbiting Carbon Observatory-2 (OCO-2) satellite provides a new opportunity to monitor CO₂ concentrations and their spatial and temporal variations at city scale. The objective of this study is to analyse the spatial and temporal distributions of CO₂ concentrations along the urban–rural gradients of Chinese cities, using the column averaged CO₂ dry air mole fraction (XCO₂) data derived from OCO-2. We used both conceptual and physical urban–rural gradients to analyse variations in CO₂ concentrations over space. The results show that the urban and rural difference in CO₂ concentrations of these cities can be monitored. And, the seasonal variations of CO₂ concentrations in these cities can also be detected using the XCO₂ data. Moreover, the variations in CO₂ concentrations along the urban–rural gradients have four main types with significant enhancements of CO₂ concentrations were observed in urban areas, urban–rural transitional areas, rural areas, and without regular patterns, respectively. The results are generally different from the common assumption that CO₂ concentrations peak in central urban areas and decline in rural areas. In conclusion, the XCO₂ data can be used to analyse the spatial-temporal variations of CO₂ concentrations along the urban–rural gradients of Chinese cities, and the results have important policy implications for mitigating CO₂ emissions.     

The evolution of sentiment analysis—A review of research topics,venues, and top cited papers

Sentiment analysis is one of the fastest growing research areas in computer science, making it challenging to keep track of all the activities in the area. We present a computer-assisted literature review, where we utilize both text mining and qualitative coding, and analyze 6996 papers from Scopus. We find that the roots of sentiment analysis are in the studies on public opinion analysis at the beginning of 20th century and in the text subjectivity analysis performed by the computational linguistics community in 1990’s. However, the outbreak of computer-based sentiment analysis only occurred with the availability of subjective texts on the Web. Consequently, 99% of the papers have been published after 2004. Sentiment analysis papers are scattered to multiple publication venues, and the combined number of papers in the top-15 venues only represent ca. 30% of the papers in total. We present the top-20 cited papers from Google Scholar and Scopus and a taxonomy of research topics. In recent years, sentiment analysis has shifted from analyzing online product reviews to social media texts from Twitter and Facebook. Many topics beyond product reviews like stock markets, elections, disasters, medicine, software engineering and cyberbullying extend the utilization of sentiment analysis.     

Air pollution,economic activity and respiratory illness: Evidence from Canadian cities, 1974–1994

Many studies have reported a relationship between urban air pollution levels and respiratory health problems. However, there are notable variations in results, depending on modeling approach, covariate selection, period of analysis, etc. To help clarify these factors we compare and apply two estimation approaches: model selection and Bayesian model averaging, to a new data base on 11 Canadian cities spanning 1974–1994. During this interval pollution levels were typically much higher than the present. Our data allow us to compare monthly hospital admission rates for all lung diagnostic categories to ambient levels of five common air contaminants, while controlling for income, smoking and meteorological covariates. In the most general specifications we find the here-observed health effects of air pollution are very small and insignificant, with signs that are typically opposite to conventional expectations. Smoking effects are robust across specifications. Considering the fact that we are examining an interval of comparatively high air pollution levels, and the contrast between our results and those that have been published previously, we conclude that extra caution should be applied to results estimated on short and/or recent data panels, and to those that do not control for model uncertainty and socioeconomic covariates.     

Modelling of urban sensible heat flux at multiple spatial scales: A demonstration using airborne hyperspectral imagery of Shanghai and a temperature–emissivity separation approach

Urbanization related alterations to the surface energy balance impact urban warming (‘heat islands’), the growth of the boundary layer, and many other biophysical processes. Traditionally, in situ heat flux measures have been used to quantify such processes, but these typically represent only a small local-scale area within the heterogeneous urban environment. For this reason, remote sensing approaches are very attractive for elucidating more spatially representative information. Here we use hyperspectral imagery from a new airborne sensor, the Operative Modular Imaging Spectrometer (OMIS), along with a survey map and meteorological data, to derive the land cover information and surface parameters required to map spatial variations in turbulent sensible heat flux (Q_H). The results from two spatially-explicit flux retrieval methods which use contrasting approaches and, to a large degree, different input data are compared for a central urban area of Shanghai, China: (1) the Local-scale Urban Meteorological Parameterization Scheme (LUMPS) and (2) an Aerodynamic Resistance Method (ARM). Sensible heat fluxes are determined at the full 6 m spatial resolution of the OMIS sensor, and at lower resolutions via pixel aggregation and spatial averaging. At the 6 m spatial resolution, the sensible heat flux of rooftop dominated pixels exceeds that of roads, water and vegetated areas, with values peaking at ～ 350 W m^? 2, whilst the storage heat flux is greatest for road dominated pixels (peaking at around 420 W m^? 2). We investigate the use of both OMIS-derived land surface temperatures made using a Temperature–Emissivity Separation (TES) approach, and land surface temperatures estimated from air temperature measures. Sensible heat flux differences from the two approaches over the entire 2 × 2 km study area are less than 30 W m^? 2, suggesting that methods employing either strategy maybe practica1 when operated using low spatial resolution (e.g. 1 km) data. Due to the differing methodologies, direct comparisons between results obtained with the LUMPS and ARM methods are most sensibly made at reduced spatial scales. At 30 m spatial resolution, both approaches produce similar results, with the smallest difference being less than 15 W m^? 2 in mean Q_H averaged over the entire study area. This is encouraging given the differing architecture and data requirements of the LUMPS and ARM methods. Furthermore, in terms of mean study Q_H, the results obtained by averaging the original 6 m spatial resolution LUMPS-derived Q_H values to 30 and 90 m spatial resolution are within ～ 5 W m^? 2 of those derived from averaging the original surface parameter maps prior to input into LUMPS, suggesting that that use of much lower spatial resolution spaceborne imagery data, for example from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is likely to be a practical solution for heat flux determination in urban areas.     

The geographic concentration of China’s e-business enterprises: where they gather and why

The geographic concentration of China’ s e-business sector represents beyond the ordinary image. The study focused on its analyses on 446 China’s e-business enterprises. The results show that a) Beijing, Guangdong, and Zhejiang are three emerging clusters whose enterprise dynamics have spread beyond the commonly mentioned major high-technology regions, and b) the regional economic status and ICT infrastructure condition are only necessary conditions of being a gathering centre, instead of sufficient conditions. Furthermore, China’s e-business sector is mainly influenced by the capital effect, and its geographic concentration has impressive combination with the location, which depends not on local public sectors’ deliberate efforts in doing-business promotions, but on the founders’ social relationships.     

An evaluation of the Mn–Ga system: Phase diagram,crystal structure,magnetism, and thermodynamic properties

The Ni–Mn-Ga alloy system is attractive due to its functional properties with potentials in various applications. However, the fundamental alloy thermodynamics of the binary Mn–Ga system is still lack of investigation. Therefore, a comprehensive evaluation of the Mn–Ga is performed in this work. Different versions of Mn–Ga phase diagrams available in the literature are reviewed. A new version of the Mn–Ga phase diagram is recommended along with possible invariant reactions. The crystal structure, magnetic transition, and thermochemical properties of intermetallic compounds are reviewed by considering available experimental and modeling such as ab initio calculations. In fact, more experimental information on the Mn-rich side is required in order to perform CALPHAD thermodynamic modeling for a reliable database. Further experiments are recommended to study the high-temperature phase equilibria between liquid, (γMn), (δMn) and Mn₂Ga(h), phase reactions between Mn₈Ga₅ and Mn₇Ga₆, and invariant reactions involving the MnGa phase. Nevertheless, the summarized information on phase equilibria, phase diagram, crystallography, magnetic transition temperature, magnetic moment, heat capacity, and enthalpy of formation can support the future thermodynamic investigation of the Mn–Ga system, which is critical for the materials design and discovery of Ni–Mn-Ga alloys.     

The evolution of knowledge-based engineering from a design research perspective: Literature review 2012–2021

Knowledge-based engineering (KBE) is a research field, which evolved in the 1980s within the context of artificial intelligence (AI), computer aided design (CAD) and computer programming. KBE is often referred to methods, processes and tools for knowledge reuse and design automation promising time and cost benefits in engineering design and originally especially in aerospace and automotive industry. Despite the long period of existence, theoretical foundations of KBE are weak and scientific literature is quite dispersed. About a decade ago, a review by Verhagen et al. collected the state of research and identified future research challenges, which has gained impact within the KBE research community. Therefore, within our review we aim at analysing the evolution of those research challenges in KBE literature during the last decade and further provide an overview of current shortcomings from a design research perspective. The analysis comprises 160 publications from the period of 2012 to 2021. Key findings from the review show, that the challenges from 2012 remain unsolved. We further derived that reuse and adoption of KBE approaches from literature is impeded by (1) a missing conceptualization of KBE research, (2) insufficient links from knowledge source to automation and (3) a tendency of insufficient distinction of the application area.     

The evolving relationship between mathematics and cryptology, 1951–1952: SCAG and the beginnings of SCAMP and NSASAB

World War II proved the value of using mathematicians as codebreakers. Both the Army’s Signal Intelligence Service (SIS) and the Navy’s OP-20-G recruited mathematicians. When the war ended and demobilization occurred, some of these mathematicians accepted academic positions or positions in industry, but some continued to serve as codebreakers. In the early 1950s, the Armed Forces Security Agency (AFSA) struggled with Soviet ciphers and with the United States’ communications intelligence (COMINT) needs for the Korean War. In 1951, in the face of a seemingly intractable problem with a Soviet cipher machine called Albatross, AFSA established a group of consultants, the Special Cryptologic Advisory Group (SCAG), which consisted of academic and industrial mathematicians and engineers. The year-long experience with SCAG led, in 1952, to AFSA’s establishment of a summer program, Special Committee Advising on Mathematical Problems (SCAMP), which enlisted academic mathematicians to work on Agency problems, and it also led to the establishment of the NSA Scientific Advisory Board (NSASAB). This article explores the immediate post-World War II evolution of the relationship between academic mathematicians and the NSA that is reflected in SCAG and in the beginnings of SCAMP and NSASAB.     

Simulation-based learning: The learning–forgetting–relearning process and impact of learning history

The results of empirical experiments evaluating the effectiveness and efficiency of the learning–forgetting–relearning process in a dynamic project management simulation environment are reported. Sixty-six graduate engineering students performed repetitive simulation-runs with a break period of several weeks between the runs. The students used a teaching tool called the project management trainer (PMT) that simulates a generic dynamic, stochastic project management environment. In this research, we focused on the effect of history recording mechanism on the learning forgetting process. Manual or automatic history recording mechanisms were used by the experimental group, while the control group did not use any history recording mechanism. The findings indicate that for the initial learning phase, the manual mechanism is better than the automatic mechanism. However, for the relearning phase, the break period length influenced the performance after the break. When the break period is short, the manual history keeping mechanism is better, but for a long period break, there is no significant difference. A comparison between the experimental group and the control group revealed that using any history recording mechanism reduced forgetting. Based on the findings, some practical implications of using simulators to improve the learning–forgetting process are discussed.     

Satellite observed seasonal and inter-annual variation of vegetation over the Kalahari,The Great Victoria Desert,and The Great Sandy Desert: 1979–1984

We present time-series observations by two spaceborne sensors over three desert regions, the Kalahari (in southern Africa), and the Great Victoria Desert and the Great Sandy Desert (in western Australia). The observations are by the Advanced Very High Resolution Radiometer on board the NOAA-7 satellite from April 1982 to December 1984, and by the Scanning Multichannel Microwave Radiometer on board the Nimbus-7 satellite from January 1979 to February 1985. The objective was to compare and contrast seasonal and interannual variation of vegetation over these three deserts using the normalized difference vegetation index and the 37 GHz brightness temperature. The seasonal variation from both sensors was found to be most pronounced over the Kalahari, followed by the Great Sandy Desert and the Great Victoria Desert. The normalized difference vegetation index was roughly identical over the two Australian deserts and was significantly higher for the Kalahari. Additionally, there was no consistent change from both sensors over the two Australian deserts, but a consistent decrease from 1979 to 1984 over the Kalahari was found in the 37 GHz microwave data.     

Object-based delineation of urban tree canopy: assessing change in Oklahoma City, 2006–2013

With a burgeoning global population, the pressures of urbanization are increasingly prevalent. The need to quantify urban greenness remains significant due to environmental impact and its relationship with human well-being. Utilizing 1 m discrete-return airborne lidar-derived digital terrain models (DTMs) and digital surface models (DSMs), aerial imagery, and lidar-imagery fusion, this study assesses vegetation, specifically tree canopy, change within Oklahoma City between 2006 and 2013. Specifically, we (1) identify an accurate object-based image analysis (OBIA) method for the detection of urban vegetation outlines, and (2) apply that method to locate and quantify vegetation change and assess spatial patterns in Oklahoma City between 2006 and 2013. The proposed OBIA approach extracts urban vegetation coverage from aerial imagery and lidar-based models with around 89% accuracy. Regarding vegetation change, Oklahoma City lost 9.69 km² (3.74 mi²) of tree canopy coverage, which accounted for a 2% loss in total greenness.     

Dynamic evolution control for synchronous buck DC–DC converter: Theory,model and simulation

This paper proposes a new control technique for synchronous buck DC–DC converter. Theory, design and implementation of the proposed control technique are provided. A new approach for converter controller synthesis based on dynamic evolution control theory is presented. In order to synthesize the converter controller, this method uses a simple analysis of nonlinear equation models of the converter. The synthesis process is simple and requires a quite low bandwidth for the controller. Therefore, this control method is suitable for digital control implementation. As an illustrative example, the synthesis of synchronous buck DC–DC converter controller is discussed in detail. The model of the synchronous buck DC–DC converter system was implemented using SimPowerSystems toolbox of MATLAB-SIMULINK. Performance of the proposed dynamic evolution control under step load change and step input voltage condition was investigated. Simulation results confirm that the proposed control method is superior to traditional PI based controller because of fast transient response and good disturbance rejection.     

The phase equilibria of the Cu–Cr–Ni and Cu–Cr–Ag systems: Experimental investigation and thermodynamic modeling

The phase equilibria of the Cu–Cr–Ni and Cu–Cr–Ag systems were investigated by a combination of key experiments and thermodynamic modeling. Eleven and fourteen ternary alloys were prepared to determine the isothermal sections of the Cu–Cr–Ni system at 800 and 1000 °C, and the Cu–Cr–Ag system at 500, 600, 650 and 700 °C, respectively, by means of X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX). The three- and two-phase regions were determined. The solubility of the third elements in the phases of the binary systems was measured. No ternary compound was found in these two ternary systems. Based on the experimental equilibria data from the literature and the present work, a thermodynamic modeling of the Cu–Cr–Ni and Cu–Cr–Ag systems was performed by the CALPHAD (CALculation of PHAse Diagrams) method. The substitutional solution model was used to describe the solution phases. A set of self-consistent thermodynamic parameters of the Cu–Cr–Ni and Cu–Cr–Ag systems was obtained. Most of the reliable experimental data can be well reproduced by the present thermodynamic modeling.     

The stickiness intention of group-buying websites: The integration of the commitment–trust theory and e-commerce success model

The success of consumer-to-business (C2B) group-buying websites (GBWs) relies heavily on consumers’ relationships with the GBWs, a topic not yet adequately investigated in the existing literature. In addition, there is a transition from the technical and/or transactional views in e-commerce studies to a relational view. However, such studies have focused on business-to-consumer contexts. By integrating the e-commerce success model and commitment–trust theory, we developed a model of GBW stickiness, which is examined using data collected from 280 GBW users. The results indicated that relationship commitment, trust, and satisfaction were key determinants of stickiness intention. Theoretical and practical implications are also discussed.