• Korea journal of population studies
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• v.8 no.2
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• pp.30-45
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• 1985

The "Dismal Theorem" (Essay) of Maithus is juxtaposed to the utopianism of both Marquis de Condorcet and of William Godwin who believed in the perfectibility of man and of the greater power of civilization over that of population. The socio-political environment that gave birth to the neo-Maltbusianism and of the economic Malthusianism is briefly sketched on, along with the discrepancy between the early theories (1978) of Malthus and the later Malthusian theory; nemely, the biological population principles of his early period runs head-on into his theory of effective demand and underconsumption. Malthus belonged to both the anti-Ricardian and the Ricardian classical tradition, and his attempt to reconcile the anomalies was not very satisfactory. Karl Marx criticized Malthus for his incon-sistent radical conservative theory of population and John Maynard Keynes came to the rescue of this Maltbusian dilemma in the 1930's, with but a morsel of success.f success.

• Journal of Food Hygiene and Safety
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• v.10 no.2
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• pp.89-95
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• 1995

Highly lethal Listeria monocytogenes, causing bromatoxism through vegetables, dairy products, meat products and shellfish etc, was examined for possible contamination in market beef. USDA, FDA, Malthus and Modified Cold Enrichment methods were used for the detection of Listeria spp.. Samples of domestic and imported market beef were collected from local meat shopsat Seoul, Korea. Total two hundreds and six of Listeria spp. were isolated and identified from beef. Among 206 isolates, the number of L. welshimeri was one hundred and twenty-one(44.8%). The numbers of isolated L. innocua, L. murrayi, L. monocytogenes, L. grayi, L. seeligeri, and L. ivanovii were 49(18.1%), 14(5.2%), 12(4.4%), 6(2.2%), 2(0.7%), and 2(0.7%), respectively. Detection rates of Listeria spp. varied among four methods. The highest detection rate of Listeria spp. in market beef was found at USDA method and that of L. monocytogenes was found at Malthus method.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.764-769
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• 1994

This study was performed to obtain fast, consistant and reliable estimation system of bacterial counts of raw milk, which effectively related to the quality of sanitaion and the condition of production at the farm. This study compared regression equation and correlation coefficient relationship between standard plate counts and data of Malthus conductance method for the detection time of total, psychrotrophs, coliform bacterial counts in raw milk. Regression equation (RE) between conductance detection time (Y) and total bacterial log counts (X) was Y=18.27651 - 2.07550X, with correlation coefficient -0.95(n=201). In coliform, RE was Y=9.320848 - 1.15598X with correlation coefficient -0.90 (n=207). Psychrotrophs had the RE of Y=29.96008-3.02487 with correlation coeffecient -0.9 (n=201). This conductance method gave results more quickly and was less labor-intensive than traditional standard plate count method.

• Communications of the Korean Mathematical Society
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• v.22 no.4
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• pp.623-640
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• 2007

The Lotka-McKendrick model which describes the evolution of a single population is developed from the well known Malthus model. In this paper, we introduce the Lotka-McKendrick model. We approximate the solution to the model using hp-discontinuous Galerkin finite element method. The numerical results show that the presented hp-discontinuous Galerkin method is very efficient in case that the solution has a sharp decay.

• Journal for History of Mathematics
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• v.24 no.2
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• pp.47-59
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• 2011

Various mathematical models have been widely studied recently in both fields of mathematics and ecology since they help us understand the dynamical process of population changes in biological species living in a certain habitat and give useful predictions. The world population model proposed by Malthus, a British economist, in his work 'An Essay on the Principle of Population' published in the period of 1789~1826 is one of the early mathematical models on population changes. Malthus' models and the carrying capacity models of Verhulst in 1845 were based on exponential type functions. The independent research field of mathematical ecology has been started from Lotka's works in 1920's. Since then various different mathematical models has been proposed and examined. This article mainly deals with single species population change models expressed in terms of ordinary differential equations.

• Food Science of Animal Resources
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• v.21 no.2
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• pp.163-168
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• 2001

This study was conducted to analyze the errors occurred between standard plate count(SPC) and Bactometer, Malthus, Bactoscan and to investigate correlation coefficient(r) between SPC and each equipments for the purpose of making new calibration curve. Correlation coefficients of three different types of equipments to SPC value were 0.71, 0.81, 0.84 respectively(n=287) and that of three types of equipments were 0.71∼0.82 relatively low. In raw milk, correlation coefficients of three types of equipments of SPC were in the range of 0.67∼0.73 below 3.0${\times}10^4$(CUF/ml) of bacterial number, and those between the three types of equipments were 0.68∼0.72. Between 3.0${\times}10^4$∼5.0${\times}10^5$(CFU/ml) of bacterial number, correlation coefficients of the three different types of equipments were 0.71∼0.81. and those between the three different types of equipments were 0.64∼0.77. Over 5.0${\times}10^5$(CFU/ml), correlation coefficient of the three types equipments were 0.66∼0.83 and those between them were 0.70∼0.85 respectively. The error of the three different types equipments to SPC value was significantly high, 37∼53% of them was under 50% of error range, and in case of raw milk less than 3.0${\times}10^4$ of bacterial number, 44∼67% of them showed over 100% of error.

• Korea journal of population studies
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• v.27 no.1
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• pp.171-201
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• 2004

Modern sciences in the West are deeply rooted in the Greek and Roman cultural heritage. Consequently, the academic achievements accomplished by the scholars of the Arabs including Persian world, the profound thoughts developed in the Indian subcontinent, and the excellent works made by the East Asian scholars have mostly been neglected in the past. This paper attempts to compare the thoughts and theories on population developed by the Western scholars with those of East Asian scolars, in chronological order, ancient, mediaeval, and modern period before Malthus. The thesis that excessive population growth may reduce output per worker, depress levels of living for the masses and engender strife is of great antiquity. In fact, overpopulation in East Asia, especially in China, goes back to very ancient times, most Confucian scholars maintained the notion of a numerical balance between population and environment. They also looked for means to check the increase in numbers. The foundations of a theory of optimum population level, fully developed in the twentieth century, can be found in their writings. Although early population thoughts in China had not advanced far in the analysis of the significance of population size and growth, it had taken only a few steps forward. At some times and to some observers, populousness appeared desirable; at other times and to other observers, it seemed all too evident that the number of people could become too great. These viewpoints foreshowed some of the later developments. The early population literatures reviewed here seem to consist of a number of quite isolated contributions. In fact, however, there may have been a greater continuity of thought than now appears, for many of the contributions may have been lost and there are many gaps in the record. An intensive review on comparing two works, those of Malthus' and Hong, Liang-chi's, are presented in this paper. Only five years before Malthus published his famous work, An Essay on the Principle of Population, Hong published his theories on population. Some of them, Hong insisted, are very similar to the Malthusian concepts of geometrical increase, natural and artificial checks of population. Despite the excellent works in the ancient period, this paper concludes with an investigation of the reasons why modem achievements in scientific areas in the East Asia have been far behind that of the West.

• Communications of the Korean Mathematical Society
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• v.18 no.3
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• pp.569-580
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• 2003

The Lotka-McKendrick equation which describes the evolution of a single population under the phenomenological conditions is developed from the well-known Malthus’model. In this paper, we introduce the Lotka-McKendrick equation for the description of the dynamics of a population. We apply a discontinuous Galerkin finite element method in age-time domain to approximate the solution of the system. We provide some numerical results. It is experimentally shown that, when the mortality function is bounded, the scheme converges at the rate of $h^2$ in the case of piecewise linear polynomial space. It is also shown that the scheme converges at the rate of $h^{3/2}$ when the mortality function is unbounded.

• Journal of applied mathematics & informatics
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• v.9 no.2
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• pp.459-517
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• 2002

The purpose of this paper is to provide a careful and accessible exposition of diffusive logistic equations with indefinite weights which model population dynamics in environments with strong spatial heterogeneity. We prove that the most favorable situations will occur if there is a relatively large favorable region (with good resources and without crowding effects) located some distance away from the boundary of the environment. Moreover we prove that a population will grow exponentially until limited by lack of available resources if the diffusion rate is below some critical value; this idea is generally credited to Thomas Malthus. On the other hand, if the diffusion rate is above this critical value, then the model obeys the logistic equation introduced by P. F. Verhulst .

• The Journal of the Korea Contents Association
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• v.20 no.6
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• pp.392-405
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• 2020

The aim of this study is to investigate the effects of income inequality on consumption expenditure in other to understand income-led growth policy. This is basically resulted in the income inequality had gotten worse since global financial crisis in many economies. Malthusian hypothesis which signifies the relationship between the income inequality and the consumption expenditure revisited for this purpose. The paper utilizes multiple break points regression and TGARCH model, and these methodologies are tentatively applied to the case of U.S and U.K. This is because that long-run time series data enables to formulate a stylized fact in general. Empirical evidence suggests that there does not exist a solid relationship among APC, income inequality by Gini coefficient, and consumption expenditure before the year of 2000, but Malthusian hypothesis is supported by weak basis in U.S while strong basis in U.K after since then. It implies that the income inequality has to be alleviated to maximize its effectiveness of the income-led growth policy.