• Title/Summary/Keyword: Describing Function

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Mathematical Models to Predict Staphylococcus aureus Growth on Processed Cheeses

  • Kim, Kyungmi;Lee, Heeyoung;Moon, Jinsan;Kim, Youngjo;Heo, Eunjeong;Park, Hyunjung;Yoon, Yohan
    • Journal of Food Hygiene and Safety
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    • v.28 no.3
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    • pp.217-221
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    • 2013
  • This study developed predictive models for the kinetic behavior of Staphylococcus aureus on processed cheeses. Mozzarella slice cheese and cheddar slice cheese were inoculated with 0.1 ml of a S. aureus strain mixture (ATCC13565, ATCC14458, ATCC23235, ATCC27664, and NCCP10826). The inoculated samples were then stored at $4^{\circ}C$ (1440 h), $15^{\circ}C$ (288 h), $25^{\circ}C$ (72 h), and $30^{\circ}C$ (48 h), and the growth of all bacteria and of S. aureus were enumerated on tryptic soy agar and mannitol salt agar, respectively. The Baranyi model was fitted to the growth data of S. aureus to calculate growth rate (${\mu}_{max}$; ${\log}CFU{\cdot}g^{-1}{\cdot}h^{-1}$), lag phase duration (LPD; h), lower asymptote (log CFU/g), and upper asymptote (log CFU/g). The growth parameters were further analyzed using the square root model as a function of temperature. The model performance was validated with observed data, and the root mean square error (RMSE) was calculated. At $4^{\circ}C$, S. aureus cell growth was not observed on either processed cheese, but S. aureus growth on the mozzarella and cheddar cheeses was observed at $15^{\circ}C$, $25^{\circ}C$, and $30^{\circ}C$. The ${\mu}_{max}$ values increased, but LPD values decreased as storage temperature increased. In addition, the developed models showed acceptable performance (RMSE = 0.3500-0.5344). This result indicates that the developed kinetic model should be useful in describing the growth pattern of S. aureus in processed cheeses.

Comparative Assessment of the Half-lives of Benfuresate and Oxolinic Acid Estimated from Kinetic Models Under Field Soil Conditions (포장조건에서 Kinetic Models로부터 산출한 Benfuresate 및 Oxolinic Acid의 토양중 반감기 비교평가)

  • Yang, Jae-E.;Park, Dong-Sik;Han, Dae-Sung
    • Korean Journal of Environmental Agriculture
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    • v.14 no.3
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    • pp.302-311
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    • 1995
  • Benfuresate or oxolinic acid, as an experimental pesticide, was applied to the different textural paddy or upland soil respectively under the field condition and the residual concentrations were determined. Six kinetic models were employed to characterize the best-fit kinetic model describing the residual pattern of benfuresate or oxolinic acid and the $t\frac{1}{2}$ estimated from each model was comparatively assessed. All of the six models explained significantly the residual patterns of the pesticides but the empirical models such as PF, EL, and PB were not recommendable for the $t\frac{1}{2}$ estimation. Among theoretical models, the residual patterns were followed in the orders of the second-order(SO)>first-order(FO)>zero-order(ZO) kinetics, judging from the size and significance of coefficient of determination and standard error. However, the multiple FO model, consisting of the fast and slow decomposition steps, was better than the single FO model for the residual pattern and the $r^2$ in this case became similar to that of SO kinetic model. Thus the multiple FO and SO models were represented as the best fit model of the experimental pesticide. The $t\frac{1}{2}$ of benfuresate estimated from the single FO kinetic model in Weolgog and Cheongwon series was 49 and 63 days, respectively, which were 20 and 13% longer than the respective $t\frac{1}{2}$ from the SO kinetic model. The $t\frac{1}{2}$ of oxolinic acid from the FO model in Yonggye and Ihyeon series were 87 and 51% longer than those from the SO kinetic model, respectively. These results demonstrated that the best-fit model representing the residual pattern of a pesticide and the resultant $t\frac{1}{2}$ might be variable with the kinds of pesticides and the environmental conditions. Therefore it is recommended that the half-life of a pesticide be assessed from the best-fit model rather than from the FO kinetic model uniformly.

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Development of a predictive model describing the growth of Staphylococcus aureus in processed meat product galbitang (식육추출가공품 중 갈비탕에서의 Staphylococcus aureus 성장예측모델 개발)

  • Son, Na-Ry;Kim, An-Na;Choi, Won-Seok;Yoon, Sang-Hyun;Suh, Soo-Hwan;Joo, In-Sun;Kim, Soon-Han;Kwak, Hyo-Sun;Cho, Joon-Il
    • Korean Journal of Food Science and Technology
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    • v.49 no.3
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    • pp.274-278
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    • 2017
  • In this study, predictive mathematical models were developed to estimate the kinetics of Staphylococcus aureus growth in processed meat product galbitang. Processed meat product galbitang was inoculated with 0.1 mL of S. aureus culture and stored at 4, 10, 20, $37^{\circ}C$. The ${\mu}_{max}$ (maximum specific growth rate) and LPD (lag phase duration) values were calculated. The primary model was used to develop a response surface secondary model. The growth parameters were analyzed using the square root model as a function of storage temperature. The developed model was confirmed by calculating RMSE (Root Mean Square Error) values as statistic parameters. The LPD decreased, but ${\mu}_{max}$ increased with an increase in the storage temperature. At 4, 10, 20 and $37^{\circ}C$, $R^2$ was 0.99, 0.98, 0.99 and 0.99, respectively; RMSE was 0.39. The developed predictive growth model can be used to predict the risk of S. aureus contamination in processed meat product galbitang; hence, it has potential as an input model for the risk assessment.

A Study on the Impact of Employee's Person-Environment Fit and Information Systems Acceptance Factors on Performance: The Mediating Role of Social Capital (조직구성원의 개인-환경적합성과 정보시스템 수용요인이 성과에 미치는 영향에 관한 연구: 사회자본의 매개역할)

  • Heo, Myung-Sook;Cheon, Myun-Joong
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.1-42
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    • 2009
  • In a knowledge-based society, a firm's intellectual capital represents the wealth of ideas and ability to innovate, which are indispensable elements for the future growth. Therefore, the intellectual capital is evidently recognized as the most valuable asset in the organization. Considered as intangible asset, intellectual capital is the basis based on which firms can foster their sustainable competitive advantage. One of the essential components of the intellectual capital is a social capital, indicating the firm's individual members' ability to build a firm's social networks. As such, social capital is a powerful concept necessary for understanding the emergence, growth, and functioning of network linkages. The more social capital a firm is equipped with, the more successfully it can establish new social networks. By providing a shared context for social interactions, social capital facilitates the creation of new linkages in the organizational setting. This concept of "person-environment fit" has long been prevalent in the management literature. The fit is grounded in the interaction theory of behavior. The interaction perspective has a fairly long theoretical tradition, beginning with proposition that behavior is a function of the person and environment. This view asserts that neither personal characteristics nor the situation alone adequately explains the variance in behavioral and attitudinal variables. Instead, the interaction of personal and situational variables accounts for the greatest variance. Accordingly, the person-environment fit is defined as the degree of congruence or match between personal and situational variables in producing significant selected outcomes. In addition, information systems acceptance factors enable organizations to build large electronic communities with huge knowledge resources. For example, the Intranet helps to build knowledge-based communities, which in turn increases employee communication and collaboration. It is vital since through active communication and collaborative efforts can employees build common basis for shared understandings that evolve into stronger relationships embedded with trust. To this aim, the electronic communication network allows the formation of social network to be more viable to rapid mobilization and assimilation of knowledge assets in the organizations. The purpose of this study is to investigate: (1) the impact of person-environment fit(person-job fit, person-person fit, person-group fit, person-organization fit) on social capital(network ties, trust, norm, shared language); (2) the impact of information systems acceptance factors(availability, perceived usefulness, perceived ease of use) on social capital; (3) the impact of social capital on personal performance(work performance, work satisfaction); and (4) the mediating role of social capital between person-environment fit and personal performance. In general, social capital is defined as the aggregated actual or collective potential resources which lead to the possession of a durable network. The concept of social capital was originally developed by sociologists for their analysis in social context. Recently, it has become an increasingly popular jargon used in the management literature in describing organizational phenomena outside the realm of transaction costs. Since both environmental factors and information systems acceptance factors affect the network of employee's relationships, this study proposes that these two factors have significant influence on the social capital of employees. The person-environment fit basically refers to the alignment between characteristics of people and their environments, thereby resulting in positive outcomes for both individuals and organizations. In addition, the information systems acceptance factors have rather direct influences on the social network of employees. Based on such theoretical framework, namely person-environment fit and social capital theory, we develop our research model and hypotheses. The results of data analysis, based on 458 employee cases are as follow: Firstly, both person-environment fit(person-job fit, person-person fit, person-group fit, person-organization fit) and information systems acceptance factors(availability perceived usefulness, perceived ease of use) significantly influence social capital(network ties, norm, shared language). In addition, person-environment fit is a stronger factor influencing social capital than information systems acceptance factors. Secondly, social capital is a significant factor in both work satisfaction and work performance. Finally, social capital partly plays a mediating role between person-environment fit and personal performance. Our findings suggest that it is vital for firms to understand the importance of environmental factors affecting social capital of employees and accordingly identify the importance of information systems acceptance factors in building formal and informal relationships of employees. Firms also need to reflect their recognition of the importance of social capital's mediating role in boosting personal performance. Some limitations arisen in the course of the research and suggestions for future research directions are also discussed.

The life and medical idea of Yoo Chang (유창(喩昌)의 생애(生涯)와 의학사상(醫學思想))

  • Kim, Soo-Yeol;Yoon, Chang-Yeol
    • Journal of Korean Medical classics
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    • v.4
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    • pp.101-126
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    • 1990
  • At early Cheong (淸) dynasty, in medical aspect by dependent on practical studying attitude that must found a theory only by an evidence, there had been a tendancy that hoped direct research of sages' mind-eye by escaping the theory of individual classes since Geum-Won (金-元) dynasty. Yoo Chang (喩昌), born in Man-Ryeok (萬曆) 12th year of Myung (明) dynasty (A.D.1583) and dead in Gang-Hee (康熙) 3rd year of Cheong (淸) dynasty (A.D.1664). The results were as follows after studying his practical idea of medicine. 1. Yoo Chang, by recognizing the ${\ll}$Sang-Han-Ro${\gg}$ has lost its true meaning after commented by Wang Hee (王熙), Lim Eog (林億), Seong Moo-I (成無巳), etc. according to Bang Yoo-Jip's (方有執) Chak-Gan-Jung-Jeong (錯簡重訂) theory, he diversified the protocal of ${\ll}$Sang-Han-Ro${\gg}$ 397 method and arranged under Six Meridian part. (六經) 2. The theory of Sam-Gang-Jeong-Rip (三綱鼎立) can be summerized Gye-Ji (桂枝) syndrome which is the case of Wind (風) has injured Wi (衛) stage, Ma-hwang (麻黃) syndrome which is the case of Cold (寒) has injured Yeong (榮) stage, Dae-Cheong-Ryong (大靑龍) syndrome which is the case both of Wind-Cold (風寒) has injured Yeong-Wi (榮衛) stage, and there has been Sam-Gang-Jeong-Rip theory by anterior medical practitioners already but the person who formally used its Sam-Gang-Jeong-Rip term is Yoo Chang. 3. Yoo Chang seized the On Byeng (溫病) by dividing three category and in Byon-Jeung-Si-Chi (辨證施治) he influenced to many aspect of establishment of later Byon-Jeung system On-Byong (溫病의 辨證體系) pertaining to Triple-Warmer by O-Dang (吳瑭) introducing Triple-Wanner Theory. (三焦理論) 4. At Chu-Jo-Ron (秋燥論) of ${\ll}$EUi-Moon-Beop-Ryo${\gg}$, while ${\ll}$Nae-Gyeong${\gg}$ describing if humidity injury Lung, then occur a disorder in it, Yoo Chang recognized that of au tuam when dryness injure Lung there occure a disorder is it so he insisted that at this case, must use Cheong-Joe-Goo-Pye method (淸操救肺法) withherbs, pertaing to Gam-Yoo-Ja-Yoon(甘柔滋潤性) property and he invented Cheong-Joe-Goo-Pye-Tang. (淸操救肺湯) 5. Yoo Chang', so called, Dae-Gi (大氣) indicates Yang-Gi (陽氣) of chest, he insisted that man's creation and every physiological activity depends on maintainence of Dae-Gi, and it integrate Yeong-Gi (榮氣), Wea-Gi (衛氣), Jong-Gi (宗氣), Jang-Boo-Ji-Gi (臟腑之氣), Gyeong-Rak-Ji-Gi. (經絡之氣) 6. Yoo Chang's expression about partical function and character of stomach, not only bolster its theory of historical physician's expression, that is stomach is. foundatness of postnatal period, but also it has corresponding aspect with modern medicine and clinic. 7. Yoo Chang emphasized "if one cure a disease, be must understood the character of disease first and use drugs later" (先議病 後用藥) phrase about of drug usage, and his theory of Geup-Rew-Man-Joo method (急流挽舟) and three therapy of Simple Ascite (單腹腸) are all unique opinion based upon this phrase mentioned above. 8. Yoo Chang's practical idea of medicine greatly influenced to Jang Ro (張璐), Hwang Won-A (黃元御), Oh Eui-Rak (吳儀洛), Joo Yang-Joon (周揚俊), etc. and theory of Sam-Gang-Jeng-Rip (三綱鼎立), Triple Warmer Theory of On Byong (溫疫의 三焦論治), Chu-Jo-Ron (秋燥論), Dae-Gi-Ron (大氣論) etc. became important object to student of Sang-Han (傷寒) and On-Byeng. (溫病) 9. Yoo Chang's Writings has more practical meaning than other physician's, especially, later the idea of Sang-Han (傷寒) and On-Byong (溫病) greatly contributed to development of Sang-Han theory and formation of On-Byong theory.

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Water Transport Characteristics of Paddy Plow Pan Soils as Estimated by Particle Size Distribution Fractal Dimension (토양입자분포 프랙탈차원을 활용한 논토양 쟁기바닥층 물이동 추정)

  • Han, Kyung-Hwa;Cho, Hyun-Jun;Hur, Seung-Oh;Ha, Sang-Geun;Cho, Hee-Rae;Jeon, Sang-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.1
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    • pp.1-7
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    • 2010
  • This study was carried out to investigate plow pan characteristics and to grasp the relationship between its particle size distribution fractal dimension ($D_m$) and water transport in paddy plow pan. Twenty four soil sampling sites with different management groups, ordinary and sandy-textured, were selected and investigated for physical properties of soils such as Yamanaka hardness in April, non-submerged condition, before rice seedling transplanting. The plow pan appearing depth and thickness was determined by penetration resistance profile. Undisturbed core samples with five replicates were sampled at plow pan layerwith 2 inch cores for measuring soil bulk density and saturated hydraulic conductivity. The particle size distribution fractal dimension ($D_m$) was calculated by the method following the procedure Tylerand Wheacraft (1992), using the USDA-based particle size analysis datawith fractions of 0-0.002, 0.002-0.053, 0.053-0.1, 0.1-0.25, 0.25-0.5, 0.5-1.0, and 1.0-2.0 mm. The plow pan of investigated fields appeared at a range from 5 to 30 cm depth, showing minimum value in sandy-textured management group and maximum value in ordinary management group. The thickness of plow pan were distributed from 5 to 17 cm, showing both minimum and maximum values in sandy-textured management group. Averagely, the plow appearing depth were deeper in ordinary management group than in sandy-textured management group, whereas the reverse in the thickness of plow pan. The particle size distribution fractal dimension ($D_m$) had higher value with finer textures, with higher fractality in coarser texture. Saturated hydraulic conductivities, $K_s$, of plow pan soils distributed from 0.5 to 1420 mm $day^{-1}$, having the highest value in sandy skeletal soils. The $K_s$ decreased with decreasing clay content and $D_m$, showing power function relationships. The coefficient of determination, $R^2$, of the fitted power functions were higher in $D_m$ as x-axis than in clay content. This means that $D_m$ could give us more effective estimation than clay content. Especially, sandy-textured paddy soils had higher $R^2$, compared to ordinary paddy soils. $K_s$ of relatively coarse-textured soils with less than 18%of clay content, therefore, was more dependent on particle size distribution than that of relatively fine-textured soils. From these results, it could be concluded that the fractal scaling gives us a unique quantity describing particle size distribution and then can be applied to estimate saturated hydraulic conductivity, especially more effective in coarse-textured soils.

Christine M. Korsgaard's Constructivism and Moral Realism (Christine M. Korsgaard의 구성주의와 도덕적 실재론)

  • Roh, Young-Ran
    • Journal of Korean Philosophical Society
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    • v.129
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    • pp.23-51
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    • 2014
  • Christine M. Korsgaard believes that constructivism can respond to moral skepticism without depending upon moral realism. The purpose of this paper is to examine Korsgaard's kantian constructivism and her positions on moral realism. According to Korsgaard moral realism cannot answer normative questions in that it sees the function of moral concepts as describing the reality and so accepts the model of applied knowledge for action. In contrast Korsgaard insists that constructivism is better at justifying normativity since it regards moral concepts as representing the solutions to practical problems and so shows that moral principles are necessarily involved in the practical problems of agency. Korsgaard's constructivism has antirealistic elements such as pure proceduralism, the constitutive model to exclude ontological, metaphysical meanings, and the account of human beings as the sources of values. In spite of those antirealistic elements it is difficult to jump to a conclusion that Korsgaard's constructivism is antirealism. Korsgaard, in the early book, The Sources of Normativity, says that kantian constructivism has something to do with a form of realism, or procedural moral realism. And in the following books she argues that constructivism is compatible with realism although she pays attention to the practical implications of constructivism and then sets aside its ontological relevance. That is, Korsgaard does not want that her constructivism results in antirealism. Korsgaard's realism, however, is too weak to be called as realism. There is, also, a question why one would rather take a constructivist approach if one holds on to realism.

Transition of the Views on the Mudang Gut Chum (shamanistic dance) (무당굿춤을 바라보는 시각의 전환 - 서울굿과 황해도굿을 중심으로 -)

  • Hong, Tea-Han
    • (The) Research of the performance art and culture
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    • no.37
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    • pp.33-60
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    • 2018
  • This article is to present that the research on the Mudang Gut Chum should be within the context of the performance of Mudang Gut and examines its meanings and implications with focus on Seoul Mudang Gut Chum and Hwanghae-do Mudang Gut Chum. Seoul and Hwanghae-do Mudang Gut Chums do not exist in the form of simple dance or movement. They feature continuity while serving the function of revealing the existence of spirit and sometimes show the process of the spirit joining the Gut ritual, which means that the Mudang Gut Chum should not be understood as the dance itself only. Instead, care attention should be paid to the status of the tune of Gut where the dance is placed, relationship between the gut and the spirit, and the flow of narrativity. Also, the Mudang Gut Chum has a lot to do with the tune. Looking at the Mudang Gut Chum simply focusing on dancing steps, and the movement of feet and/or hands fails to gain an accurate understanding of the fundamentals of the Mudang Gut Chum. Closely connected to the tune, which is also associated with the grade of the spirit, the dance shows a variety of performances conducted by entering the Gut ritual of the spirit. In that respect, complex views on the Mudang Gut Chum are required. The same applies to the hereditary shaman Mudang Gut as well. The Korean Mudang Gut Chum has a slight difference between the Gangshinmu gut and the hereditary gut but is in basically the same aspect. The Gut Chum holds its meaning in the flow of gutgeori (tune or dance performed during exorcism, a shaman song) and delivers its own meaning in connection with the tune. It is definitely meaningful to focus on the individual movements of a dancing shaman but one should be able to derive the network of meanings that such movements have within the performance of the gutgeori, which means that intensive studies on the field performance and circumstances should be completed before studying the Mudang Gut Chum. In addition, the Mudang Gut Chum discloses the characteristics of the performance group. The Mudang Gut Chum exists in a complex manner. With respects to the status of the spirit, it shows the characteristics of the performance group. It represents the progress of Gut while closely connected with the tune. Therefore, the way of describing the Mudang Gut Chum should be far more than just simply keeping the dance notations. With this in mind, one should investigate and record the Mudang Gut Chum.