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The paper explores and characterizes antifragility in simple inventory systems exposed to demand variability, providing the initial inroads to operationalizing antifragility in the context of inventory management. Antifragility refers to the feature of a system that can benefit from uncertainty, rather than suffer from it. The paper expands the concept of inventory beyond that of risk mitigation and towards one of enabling antifragility.

The study employs analytical and simulation modelling of an inventory system with two classes of demand. To separate the influence of factors, a simple inventory policy with a range of fixed order quantities is modelled, allowing for the identification of antifragile regions in an experimental space.

Outputs uncover a variety of performance outcomes, ranging from settings where additional inventory yields no benefit, to areas where additional inventory results in increasing normalized profit with increasing uncertainty, demonstrating antifragility. In between these regions, increases in normalized profit are bounded, and confined to specific regions.

This research expands academic understanding of inventory as a vehicle to achieving antifragile outcomes. Although this paper does not solve for an optimal policy as typical inventory research does, it instead characterizes the antifragile outcomes within simple inventory systems. Further research should be carried out to investigate antifragility in settings of greater complexity and design ordering policies leveraging inventory towards a gain from uncertainty.

Typically, inventory is used to buffer against uncertainty, and, with a given amount of inventory, the performance is expected to degrade with increasing variability. In this paper, the authors demonstrate that certain levels of additional inventory can result in antifragility and increase profitability as uncertainty increases, extending beyond traditional conceptualizations of inventory and uncertainty.

Empirical research into designing antifragile outcomes is limited, with very few examples of increasing performance with increases in uncertainty. This article presents an initial empirical exploration of how additional inventory can result in antifragility.

This study aims to combine information about sea level rise (SLR), the probability distribution of storm surge, a flood damage function and the value of property by elevation along the coast of selected cities to measure expected flood damage. The selected six cities all have nearby long-term tidal stations that can be used to estimate the probability distribution of floods. The model is calibrated to each city. The study then compares the cost of building higher seawalls today along the coast versus the benefit of each wall (the reduction in expected flood damage).

The combination of coastal storms and SLR has led to extensive flood damage across American cities. This study creates a simple generic model that evaluates whether seawalls would be effective at addressing this flooding problem. The paper develops an approach that readily measures the expected flood benefits and costs of alternative coastal seawalls. The approach takes account of near term SLR and the probability distribution of storm surge. The model finds seawalls are effective only in cities where many buildings are in the 25-year flood plain.

Cities with many buildings built on land below 2 m in elevation (the 25-year flood plain) have high expected flood damage from storms and SLR. Cities which already have many buildings in this flood plain would benefit from seawalls. Assuming seawalls are built above the high tide line, the optimal wall height that maximizes net benefits is between 0.9 to 1.2 m. These relatively low seawalls block 70%–83% of expected flood damage in these cities. Fair flood insurance is the least cost strategy for handling the remaining damages that overtop the optimal seawalls.

The analysis evaluates whether or not to build a seawall the length of each city at high tide lines. However, the analysis also finds several long stretches of coast in two cities where a wall is not warranted because there are few vulnerable buildings. Future analyses should consider seawalls in more spatially detailed sections of each city. Each section could then be analyzed independently. Whether or not more complex hydrodynamic models are needed to evaluate coastal resilience planning should also be explored. Alternative solutions such as planned retreat and nature-based solutions should be compared with seawalls in future studies as well.

Cities should be careful to avoid development in the 25-year flood plain because of high expected flood damage. Cities that have low elevation areas subject to frequent flooding should consider seawalls to reduce frequent flooding. Because they are very costly and have low expected benefits, high walls that can stop a one-hundred-year storm are generally not worth building.

The analysis reveals that the most important factor determining the vulnerability of cities along the eastern coastline of the USA is the number of buildings built below 2 m in elevation (the 25-year flood plain). Cities should use zoning to discourage further development in the 25-year flood plain. Cities which already have many buildings in this flood plain would benefit from city-wide seawalls. Assuming these walls are built at mean high-high tide, the optimal height of current seawalls should be relatively modest – averaging about 0.9–1.2 m above ground. Using fair insurance for the remaining risk is less expensive than building taller walls. In particular, the cost of seawalls that protect against a major hurricane surge are over three times the expected benefit and should not be built. As decades pass and observed sea level progresses, seawalls and the boundary of the 25-year flood plain should be reevaluated.

This paper develops a coastal flood model that combines SLR and the probability distribution of storm surges with the value of property by elevation to estimate the expected damage from storm surge. The model is relatively easy to calibrate making it a practical tool to guide city flood planning. The authors illustrate what insights such a model gives about coastal resilience to flooding across six cities along the Eastern US coastline.

This paper aims to focus on the inclusion of the frequency behavior of grounding system effect on surge arrester (SA) model parameters’ estimation.

The grounding system impedance and its frequency behavior are the factors that have influence on the SA performance. Up to now, the grounding system impedance effect and the frequency behavior of the soil parameters have not been studied for the estimation of the parameters of the SA frequency-dependent model. In this paper, the grounding system’s influence on the SA dynamic model has been simulated for rod- and counterpoise-shaped electrodes. Particle swarm optimization with a grey wolf optimization algorithm has been implemented as an optimization algorithm to adjust the parameters of the SA dynamic model.

The results show that the frequency behavior of the grounding impedance and soil electrical parameters can impress the optimum parameters of the SA frequency-dependent model and should be considered for more reliable results. Also, the results evidence that the proposed optimization method provides more accurate results compared to other optimization methods.

To the best of the authors’ knowledge, this work is one of the first attempts to investigate the effect of frequency grounding system on SA frequency-dependent model parameters.

The Sundarbans is a unique ecosystem, the most expansive mangrove system in the world covering the Ganga–Brahmaputra–Meghna delta system and spread over 10,000 sq.km across India and Bangladesh. The Indian Sundarbans have been witnessed to large-scale conversion of mangroves to settled agriculture and steady growth of population over the decades. With time, while population growth has taken place, there has been no significant change in the development scenario, as the agriculture and fishing dependent communities have remained trapped in the vicious cycle of poverty. Its deltaic location and its position in the path of cyclones, tidal surges and seasonal floods have made the people and landscape of Sundarbans more vulnerable than ever before. Cyclones affecting this region have grown both in frequency and intensity over the years and have caused devastation to the land, homes, lives and livelihoods. The problem of salinity has also affected the region relentlessly. Given this scenario, scenario of progressing vulnerabilities, livelihood losses have led to a gradual increase in out-migration of the adult male population. This disaster-led outmigration from Sundarban region as a whole has affected the social fabric of displaced communities to a great extent. This chapter makes an attempt to discuss results of sample surveys across six villages in three CD Blocks of Sagar, Gosaba and Kultali to trace the nature and dimension of the migration patterns of the region.

Cannabis as a recreational drug is prohibited in Nigeria. Consequently, the open use of cannabis attracts both formal and informal sanctions. As such, there is much stigma on users' faces across social spaces. This has led to innovations in drug use. Recently, non-medical use of tramadol has been rising across each of the gender categories. This study aims to understand (1) tramadol use prompts, (2) the sudden surge in gendered recreational use of tramadol and (3) the gendered challenges of recreational tramadol use among Nigerian university students.

Data were collected between December 2021 and October 2022. The researcher conducted 20 semi-structured interviews, with participants chosen purposefully from acquaintances and others selected through chain referral. The selection criteria included knowledge of a particular tramadol tablet and willingness to participate. This study got ethical approval from the Anambra State Ministry of Health (Ref: MH/AWK/M/321/354) and oral consent was obtained before the interviews. The participants were assured of confidentiality. The interviews were conducted in English (the formal Nigerian language) and lasted between 30 and 65 min. The data collected were transcribed and coded manually, and themes generated.

Findings suggest that peer pressures accounted for entry-level drug use. However, cannabis-related stigma is attributed to the surge in tramadol use across gender categories. Furthermore, academic pressure and sexuality are major reasons for tramadol use. The challenges associated with tramadol use include headaches and addiction.

This study, to the best of the author’s knowledge, presents alternative data on the surge in tramadol use among Nigerian university students.

Australian Securities Exchange (ASX) initial public offerings (IPOs) are an important source of early-stage capital and have also driven a substantial increase in main-board listed companies post-millennium. By contrast, Australian venture capital (VC) funding has remained largely dormant. The opposite has occurred in the US: IPOs have fallen by half, and VC funding has surged. The authors examine the reason for this divergence between ASX IPO and US VC systems that, with their supporting ecosystems, have many features in common and function similarly. The authors explore the potential factors that could explain the US VC surge vis-à-vis Australia's VC stagnation.

The authors’ analysis is predominantly qualitative. The authors describe the Australian listing process and its similar features and functions as for the prototypical VC. The authors also describe the developments in US VC driving its recent exceptional surge and highlight that such developments have not yet materialised on the Australian scene, where early-stage IPOs have served as a substitute.

The ASX's structure and ecosystem have been critical to its success in fostering early-stage main-board listings. While the US has succeeded in alternatively growing VC, there is an increasing concern that the latter has occurred partially because valuations are stretched, tax concessions for carried-interest capital gains are too high and corporate control benefits are becoming increasingly diluted. These developments could have important implications for Australia, where VC structures are currently being reviewed.

To the best of the authors’ knowledge, no prior study has attempted to bridge the broad differences in IPO and VC funding trends for early-stage companies in Australia and the USA.

This article intends to analyse the explanatory power of the Travel and Tourism Competitiveness Index (TTCI) and some of its constituent factors on national success metrics in managing the initial surge of the COVID-19 pandemic.

The authors study the outbreak control effectiveness of 132 countries during the first semester of 2020. The authors apply generalized linear regression models and weighted least squares models using 6 COVID-19-related dependent variables, 9 TTCI-related independent variables and 12 control variables.

The results suggest that countries with superior TTCI values and selected constituent factors have the highest daily averages of coronavirus infections and fatalities per million and the highest speed rates of COVID-19 spread. The authors also find that these countries have the shortest government response time, the lowest daily average of the social restrictions index and the shortest time from the first case reported in China to the first case reported nationally.

To the best of the authors' awareness, no previous study exists analysing the statistical relationship between the TTCIB and some of its constituent factors with the selected metrics of national success at managing the initial surge of the COVID-19 pandemic. This fact represents the primary evidence of this article's unique contribution.

本文擬分析旅行及觀光競爭力指數、以及其部份構成因素，如何影響有關國家在新型冠狀病毒肺炎大爆發初期控制病毒傳播方面的成功指標。

我們就132個國家於2020年上半年控制肺炎爆發方面的表現進行研究。我們以廣義線性回歸模型和加權最小平方法進行分析研究，當中使用了六個與新型冠狀病毒肺炎有關的因變數、九個與旅行及觀光競爭力指數有關的自變數、和12個控制變量。

研究結果暗示、在擁有優越的旅行及觀光競爭力指數值和選定的構成因素的國家，以百萬人來計算，每日冠狀病毒感染及死亡的平均數字是最高的; 而且，新型冠狀病毒肺炎的傳播速度也是最高的。研究結果亦顯示、在這些國家，政府反應所需的時間是最短的，社會限制指數的日均值是最低的，以及首宗在中國被報導的個案與首宗在有關的國家被全國性地報導的個案之間的時間距是最短的。

盡作者們所知，從前似沒有相關的研究、以國家在新型冠狀病毒肺炎大爆發初期成功控制病毒傳播的選定指數、來分析旅行及觀光競爭力指數與其部分構成因素之間的統計關係; 這正是本文所作獨特貢獻的基本證據。