• Journal of Preventive Medicine and Public Health
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• v.44 no.1
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• pp.22-31
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• 2011

Objectives: We examined gender differential changes in employment-related health inequalities according to occupational position (professional/nonprofessional) in South Korea during the last decade. Methods: Data were taken from four rounds of Social Statistical Surveys of South Korea (1995, 1999, 2003, and 2006) from the Korean National Statistics Office. The total study population was 55435 male and 33913 female employees aged 25-64. Employment arrangements were divided into permanent, fixed-term, and daily employment. Results: After stratification according to occupational position (professional/nonprofessional) and gender, different patterns in employment - related health inequalities were observed. In the professional group, the gaps in absolute and relative employment inequalities for poor self-rated health were more likely to widen following Korea's 1997 economic downturn. In the nonprofessional group, during the study period, graded patterns of employment-related health inequalities were continuously observed in both genders. Absolute health inequalities by employment status, however, decreased among men but increased among women. In addition, a remarkable increase in relative health inequalities was found among female temporary and daily employees (p = 0.009, < 0.001, respectively), but only among male daily employees (p = 0.001). Relative employment-related health inequalities had clearly widened for female daily workers between 2003 and 2006 (p = 0.047). The 1997 Korean economic downturn, in particular, seemingly stimulated a widening gap in employment health inequalities. Conclusions: Our study revealed that whereas absolute health inequalities in relation to employment status increased in the professional group, relative employment-related health inequalities increased in the nonprofessional group, especially among women. In view of the high concentration of female nonstandard employees, further monitoring of inequality should consider gender specific patterns according to employee's occupational and employment status.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.12
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• pp.1154-1164
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• 2010

As an useful application in broadcasting services, the targeting service has been mainly studied to improve the service satisfaction and user usage in various media service environments based on user profile, preferences, and usage history. Targeting service is expanding its domain from broadcasting contents to interstitial contents and from fixed TV devices to mobile devices. Service data also include advertisement data, coupon, and information about media contents as well as simple broadcasting data. In this paper, the targeting data service is designed and implemented on articles, advertisement and broadcasting information on the basis of the user information. To adapt this to web-based media contents, information on user profile, preferences, and usage history is newly defined on the basis of the user metadata developed in TV-Anytime Forum and the user information defined in OpenSocial. The targeting data service is implemented to generate user preferences information and usage history pattern based on the similarity among user preference, contents information, and usage history. Based on performance evaluation, we prove that the proposed targeting data service is effectively applicable to web-based media contents as well as broadcasting service.

• Journal of Korean Society of Transportation
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• v.17 no.5
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• pp.19-32
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• 1999

In this study, the trip characteristics of workers in the city are systematically analyzed. The trip behaviors and socioeconomic characteristics of workers are analyzed using Person Trip Survey Data of 1988 and 1992 in Taegu Metropolitan area. With the results of behavioral analyses, the daily travel pattern of workers is shown as one tour contained two trips and it is relatively simple and stable. Also the rate using the same mode in a day is Presented as high ratio. So, it can be explained that the choice of worker\`s first trip is fixed his/her travel mode for his/her daily travel mode. Based on these analyses, the mode choice model for workers is developed by applying the Multi-nominal Logit Model with the choice set of bus, taxi, and car. The explanatory variables of this model include sex, age, auto, travel time, and cost. Empirical tests of the model show encouraging results. After that, the temporal transferability of the model is examined by the Pairwise t-test and five indexes far the model of 1988 and 1992. The results of examination are satisfied with each significance level of the explanatory variables and five indexes. Therefore. it can be concluded that the temporal transferability of this model developed in this study is resonable.

• Research in Plant Disease
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• v.21 no.4
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• pp.268-272
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• 2015

Bacterial leaf blight caused by Pseudomonas syringae pv. porri is one of the major bacterial diseases of garlic (Allium sativum). In South Korea, the disease has only been observed in garlic-growing regions of Jeju island. The spatial distribution pattern of the disease was analyzed by binary power law, in which the natural logarithm of the observed variance is regressed on the natural logarithm of the binomial variance. The estimated slope (b=1.361) of the regression was greater than 1 which meant that the diseased plants were aggregated. The sequential sampling plans were developed for estimating the mean incidence rate ($p_m$) and classifying the mean incidence as being below or above the critical incidence rate ($p_t$). These results could be used on more efficient and higher precisive sampling for bacterial blight of garlic compared to fixed sample sized sampling.

• Korean Journal of Community Nutrition
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• v.17 no.3
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• pp.280-289
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• 2012

The objective of this research was to explore the influences of 'having a meal with someone' on individuals' eating pattern. Eating is not a simple matter of energy intake but also serves to anchor daily routines being cultivated by people and society. This study was conducted using a cross-sectional eating behavior survey of university students (N = 893, 380 men, 513 women) aged 20 to 24 years. Results were analyzed and presented as frequencies, means and ${\chi}^2$-test with SPSS 14.0. Differences in dietary habits by commensality and solo-eating were observed; Students who ate alone, spent 15 min for a meal and ate convenience food items when they didn't feel hungry. Compared to students who ate alone, those who ate together with someone spent 30 min for a meal and ate more amount of food. Eighty percent of respondents ate more various menus in commensality than solo-eating. They felt lonely when they ate alone and preferred to eat together. In conclusion, university students start to decide and select their own meals by themselves after junior and high school food services which are fixed with regard to menu and the amount. Dietary habits of Koreans rapidly changed concomitant with social changes over the past half century. Governments and health experts recognize that unbalanced meals cause lifestyle-related diseases, in particular obesity. Our research findings will contribute to more comprehensive efficient nutrition education programs in order to prevent obesity and other lifestyle-related diseases in early stages of adulthood.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.10a
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• pp.103-112
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• 1996

Optimal pricing research in general has been focused on profit maximizing strategy under the given product life-time T. Here we have tried to study the effect of uncertain product life-time on dynamic optimal pricing strategy. In reality, the life-time of product is more likely to be uncertain and not known as well. In terms of approximating the model to the concerned reality, so-called model validity, it seems to be more desirable to consider the uncertainty of product life-time into the optimal pricing strategy model, For this purpose, we tried two different approaches. One is to consider diverse product life-time probability functions under fixed life-time T. In this case, we might have the same product life-time as the previous study, but the process could be different in the expectation of product's discontinuity. The other is that life-time itself is not determined and thus it is the situation in which we can only decide optimal price on incremental basis. The former is the situation in which although we got some strong guess on life-time of a certain product, the pattern of expected life-time probability could be different. The question is what could be optimal pricing strategies on such different product life-time situations. But since in the latter, we don't assume any idea on the life-time of product. proper optimal pricing could be derived only from the past prices and diffusion information. While the latter seems to be safer in the aspect of model assumption, the former could be more realistic because we might have more or less a prior knowledge on the product life-time itself.

• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.85-94
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• 2002

Computational flow dynamics(CFD) has been frequently applied to the waste incinerators to understand the flow performance for various design and operating parameters. Though it needs many simplifications and complicated flow models, the reasonability of its results is not fully evaluated. For example, the inlet condition is calculated from an arbitrarily assumed properties of combustion gas release from the waste bed, since the combustion in the bed is difficult to be predicted. In this study, the computational modeling and calculation procedures of CFD for the grate type waste incinerator were evaluated using comparative simulations. Though the assumption method on the generation of the combustion gas directly affected the temperature and gas species concentrations, the overall flow pattern was dominated by the secondary air jets. The gaseous reaction could be included by assuming the release of the products of incomplete combusion from the bed. However, the reaction effficiency cannot not be directly evaluated from the species concentration, since it is not possible to simulate the actual co-existence of fuel rich or oxygen rich puffs over the bed. In predicting the turbulence, the higher order model, such as Reynolds stress model, gave difference shape of local recirculation zones, but similar results was acquired from the standard $k-{\varepsilon}$ model. Introducing radiation model was required for accurate temperature prediction, but it also caused heat imbalance due to the fixed temperature of the inlet, i.e. the waste bed. Thus, the computational modeling procedures on incinerators and the analysis of the predicted results should be progressed carefully. Though not validated experimentally, current simulation method is capable of comparative evaluation on the flow-related parameters such as the furnace shape and secondary air injection using identical inlet conditions. Quantitative analysis using measures of the residence time and mixing is essential to compare the flow performance efficiently.

• The Journal of the Korea Contents Association
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• v.16 no.10
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• pp.636-644
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• 2016

The actress of the movie is an operating system called Samantha. She only has a voice in the movie. Theodore, the main actor writes letters for his clients. He got married Katherin after dating for years but they failed to maintain their relationship. It was hard for them to grow with distance. On the contrary, the learning OS doesn't have any fixed pattern and any limits, so it becomes the ideal partner for him. Since she was accessed by him, Samantha has expanded her ability rhizomatically. She could have sex with human and philosophical debates with a departed philosopher. While they have relationship, Theodore experiences the expansion of his conscience. Love cannot be confined in a small box. After realizing how to love people around him, he sends a love letter to Katherine with all his heart. The meaning of co-existing with A.I. and human is to have a chance to introspect our inner side of mind more deeply.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.3
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• pp.465-479
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• 2020

Objective: This study performed a meta-analysis of published trials to determine the effects of zinc on the immune response and production performance of broilers. Methods: A database was built from published literature regarding the addition of zinc forms or doses and their relation to the immune response and production performance of broilers. Different doses or forms of zinc were identified in the database. The recorded parameters were related to the immune response and production performance. The database contained a total of 323 data points from 41 studies that met the criteria. Then, the data were processed for a meta-analysis using a mixed model methodology. The doses or different forms of zinc were considered fixed effects, different studies were treated as random effects, and p-values were used as the model statistics. Results: An increase in zinc dose increased (p<0.05) pancreas metallothionein (MT) and zinc concentrations in the plasma, tibia and meat, all in quadratic patterns, but linearly decreased (p<0.05) the heterophil/lymphocyte (H/L) ratio. Regarding the different zinc forms, both inorganic and organic zinc increased (p<0.05) the zinc concentrations in the plasma and tibia, the calcium and phosphorus contents in the tibia, and the antioxidant activity of superoxide dismutase in meat as compared to control. An increase in zinc dose increased average daily gain (ADG) and decreased feed conversion ratio (FCR) following a quadratic pattern (p<0.05). Inorganic and organic zinc decreased (p<0.05) FCR and H/L ratio than that of control, but these two forms were similar for these parameters. Conclusion: Zinc addition has a positive impact on immunity and broiler production. Zinc can suppress stress and inhibit the occurrence of lipid peroxidation in broilers, and it can also improve ADG, FCR, and the quality of broiler carcasses.

• Ocean and Polar Research
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• v.30 no.3
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• pp.261-275
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• 2008

The profile of a fixed site at station M ($34.77^{\circ}N,\;129.13^{\circ}E$) in the Korea Strait was studied from March 2006 to February 2007. The aim was to understand the relationship between the annual thermal stratification pattern and seasonal variation in phytoplankton community structure. Physicochemical factors including temperature, salinity and nutrient concentrations, which strongly influence the proliferation and diversity of phytoplankton, were measured. The study period was divided into three due to the characteristic of thermohaline structures; mixed I (March-May 2006), stratified (June-November 2006) and mixed II(December 2006-Feburuary 2007). Diatoms dominated during the mixed I (89%) and II (48%) periods, while nanoplankton group occupied over 83% of total population during the stratified period. The dominant species during the mixed I and II was Chaetoceros socialis (47% and 29%, respectively), while during the stratified period Gyrodinium sp.(4%) was the most dominant. Averaged total chl a concentrations during the mixed I and II periods were 0.61 mg $m^{-3}$ and 0.72 mg $m^{-3}$, respectively, which were at least two-fold higher than that during the stratified period (0.30 mg $m^{-3}$). The vertical mixing and convection process of the water column induced nutrient supply from the bottom layer to the euphotic zone. It also led to the dominance of diatoms during the mixed periods, whereas small phytoplankton prevailed over large phytoplankton as stratification blocked the upward movement of nutrients to subsurface during the stratified period. During the mixed I and II periods, microplanktonic chl a dominated concentrations (50% and 48%, respectively), while picoplanktonic chl a occupied over 37% of total chl a during the stratified period.