• Journal of Distribution Research
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• v.14 no.1
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• pp.45-65
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• 2009

As a number of people using the internet for their shopping steadily rises, it is increasingly important for retailers to understand why consumers decide to buy products via online or offline. The main purpose of this study is to develop and test a model that enhance our understanding of how consumers respond future online and offline channels for their purchasing. Rather than merely adopting statistical models like most other studies in this field, the present study develops a model that combines double-cohort method with multinomial logit model. It is desirable if one can adopt an overall encompassing criterion in the study of consumer behaviors form diverse sales channels. This study uses the concept of cohort or aging to enable this comparison. It enables us to analyze how consumers respond to online and offline channels as people aged by measuring their shopping behavior for an online and offline retailers and their subsequent purchase intentions. Based on some empirical findings, this study concludes with policy implications and some necessary fields of future studies desirable.

• Environmental Mutagens and Carcinogens
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• v.9 no.2
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• pp.97-109
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• 1989

살균제 Captan, 살충제 Diazinon, MEP, Malathion 및 EPN 의 단독 처리 그리고 Captan 반복처리와 이들 살충제와 서로 다른 조합으로의 동시적, 시간적 복합처리가 E. coli WP2S(uvrA-, trp-) 균주의 돌연변이유발 빈도 및 생잔율에 미치는 영향을 검토하여 다음과 같은 결과를 얻었다. 1. Captan, Diazinon, MEP, Malathion, EPN 및 UV 의 동시적 복합처리는 이들 농약의 단독 처리에서 보다 E. coli WP2S (uvrA-, trp-)균주의 돌연변이유발빈도가 높았고 이들 농약의 단독처리효과를 합한 가산적 영향으로 나타났으며, 동일조건하에서 이들 농약의 처리농도를 배로 늘렸을 때는 배가효과를 보였으나 이 균주의 증가된 돌연변이 유발빈도는 cinnamaldehyde 30ng 및 60ng/ml 그리고 tannic acid 50ng/ml 배지로 각각 첨가했을 때 감소되었고 생잔율은 증가되었다.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.258-259
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• 2000

최근 감소 추세에 있는 연안수산자원을 인위적으로 증가시키기 위해서 유용생물의 치어를 생산하여 방류를 통해 수산자원을 증가시키고자 노력하고 있다. 인공종묘를 방류하여 자연자원을 증가시키려는 경우, 고려해야 할 요소가 많지만, 그 중에서도 먹이환경은 치자어의 방류 후 생잔율을 결정하는 중요한 변수가 될 수 있다(광전ㆍ 야구, 1986ㆍ1988). 따라서 방류를 통해 수산자원을 효과적으로 증가시키기 위해서는 어린 시기의 먹이 환경에 대한 많은 연구가 필요하다. 본 연구는 치자어의 성육장이 되는 연안 쇄파대에서의 먹이생물이 되는 갑각류의 분포에 관해 조사하였다. (중략)

• Korea journal of population studies
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• v.25 no.2
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• pp.163-192
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• 2002

Residential overcrowding, also called density, measured as more than one person per room, is a important variable as a principal indicator of inadequate housing. We investigated how immigrants in the US are assimilated to the host society through a lens of housing density. We estimated the probability of living in overcrowded housing of Korean, Chinese and Japanese immigrants armored with the 1980 and 1990 Public Use Microdata Sample(PUMS, A, 5%) in the US. Along with economic effects, we also consider life-cycle effects on the indicator. We applied "double cohort" method that enables duration of immigration effects to be separated from aging effects, which captures family size fluctuations due to life-cycle effects. The study found that cohort trends sharply changed during 10years. The 1970's immigrants are more likely to live in overcrowded housing than the pre-1970 immigrants. The pre-1970 immigrants are more likely to live in overcrowded housing than native-born persons. This may be explained by different assimilation processes driven by the disparities of individual human capitals or cultural differences among the ethnic groups. Especially, Korean experienced a sharp decline in overcrowding between 1980 and 1990. We also found that the major determinants that affect the level of housing density are years since migration, income, and gender. The present study concluded with some future studies related to the Korean immigrants abroad.ts abroad.

• Journal of Korean Society of Rural Planning
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• v.12 no.3 s.32
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• pp.39-42
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• 2006

The purpose of this study is to develop rural population model adapting cohort survival method with sift-share effects. Administrative district in this study is below Myun: about 2,000 population. Population data of rural area in 1990, 1995, and 2000 by age cohort were selected for applying developed model. Damping coefficient from population data was calculated as 7% and results applying this coefficient in rural population data below the error from 12% to 1.06%. In detail, most of cohorts fitted with developed model except from 15 to 29 age groups. Application result of small population area; DaesulMyun revealed that main factor of population change is not natural change but migration.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.139-144
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• 1969

1. In order to obtain useful mutants such as early maturity, resistance to lodging, high protein and oil content, and capability of high yield, dormant seeds of two soybean varieties, Jang Dan Baik Mok and Clark, were treated with ${\gamma}$-ray, Ethyl Methane Sulfonate(EMS), Ethylene Imine(EI)and combinations of ${\gamma}$-ray and EMS or EI. 2. The germination rate and survival rate in a variety Jang Dan Baik Mok were significantly decreased with ${\gamma}$-ray treatment while it was not the same in the Clark variety. A significant decrease for seedling height measured at 14 and 21 days after sowing was found with the increase of ${\gamma}$-ray dose in both varieties. 3. Germination rates in both varieties were significantly decreased as EI concentration increases, particularly severe damage in germination was observed at 0.008 Mo. concentration. Germination rate damages were found with EMS concentration increases in the variety Jang Dan Baik Mok while no regular responses in seedling height were observed in the variety Clark. 4. Germination rate was significantly lowered with the combined treatment of EMS and ${\gamma}$-ray 24KR than that of EMS alone. In the treatments of ${\gamma}$-ray with three levels of EI concentration, the combined treatments except 24KR+EI 0.002 Mol. resulted in better germination than of EI alone. In both varieties, significant reduction in seedling height was observed in the combined treatments of ${\gamma}$-ray with various concentrations of EMS, whereas stimulation effect on seedling height was found with treatment of ${\gamma}$-ray EI +0.08Mol. 5. Germination rate, survival rate, and plant height as criteria of radio sensitivity, variety Jang Dan Baik Mok is moze sensitive to ${\gamma}$-ray, EMS, and EI than the variety Clark, and the varietal difference in responsibility to mutagen may be due to the genetic-constitution of the varieties.

• Journal of Aquaculture
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• v.16 no.2
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• pp.118-123
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• 2003

This study was conducted to investigate the disinfection effects of chlorine dioxide ($ClO_2$) on 4 fish pathogenic bacteria (Vibrio anguillarum, Edwardsiella tarda, Streptococcus sp. and Staphylococcus sp.) isolated from infected olive flounders. The bacteria were exposed to different concentrations of ClO$_2$ (0.129, 0.246 and 0.455 ppm) and response times (0.5, 1, 3, 5 and 10 min), and then were incubated for 12 hr. The effective disinfection concentrations of $ClO_2$ against experimental bacteria by $ClO_2$ for 0.5 min were observed with 0.455 ppm for Staphylococcus sp., 0.246 ppm for V. anguillarum and E. tarda, and 0.129 ppm for Streptococcus sp., respectively. The duration of exposure at low concentration of $ClO_2$ increased for the disinfectant ability to experimental bacteria.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.587-593
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• 1998

To elucidate anti-tumor promoter from seaweed, the anti-tumor promoting activity of Ecklonia stolonifera, Undaria pinnatifida and Laminaria japonica extracts were determined by Epstein-Barr virus (EBV)-early antigen (EA) induction caused by a tumor promoter, teleocidin B-4. The methanol extracts of seaweed were subsequently fractionated with diethyl ether, distilled water, chloroform and ethyl acetate. Among the solvent fractions tested, chloroform and ethyl acetate fraction of E. stolonifera showed a high anti-tumor promoting activity at the levels of 88.0 and $85.9\%$ by the addition of 20 ${\mu}g/m{\ell}$, respectively. To characterize anti-tumor promoters from solvent fractions of E. stolonifera, the effects of phenols, chlorophyll derivatives and carotenoids on the anti-tumor promoting activity were investigated. Phenols, such as bromophenol and phloroglucinol showed anti-tumor promoting activity of $57\~66\%$ at 20 ${\mu}g/m{\ell}$. Pigments, such as chlorophylls and carotenoids exerted high anti-tumor promoting activities. Chlorophyll a and pheophorbide a exhibited the activity of $77.4\%$ and $66.6\%$ at 5${\mu}M/m{\ell}$, respectively. The active compounds of carotenoids were tentatively identified as lutein and $\alpha-cryptoxanthin$ from the profiles of visible spectra and R_f value of their authentic compounds, and showed anti-tumor promoting activities of $76.9\%$ and $84.4\%$ at dose of 20 ${\mu}g/m{\ell}$, respectively.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.1020-1025
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• 2004

In previous paper, contaminations of food-borne pathogenic bacteria of Saengshik was found to occur during processing, because detection rates of food-borne pathogenic bacteria in final products were higher than those of raw materials. In this study, methods to reduce food-borne pathogenic bacteria and improved manufacturing process were developed for microbial safety of Saengshik. Food-borne pathogenic bacteria in raw materials were reduced to about 0.5-2.0 log cfu/g when seven kinds of raw materials were washed with electrolyzed water and ozonated water, but food-borne pathogenic bacteria could not be removed completely. After improvement of manufacturing process, numbers of food-borne pathogenic bacteria were same or decreased to levels of raw materials. Gaseous ozone and Biocon could control air-borne bacteria under $1{\times}10^1$ cfu/1000 L of air in pulverization and mixing rooms.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.423-429
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• 2001

Prediction of the variation in annual biomass was conducted for the white croaker. Argyrosomus argentatus in Korean waters using leslie Matrix, based upon fishery data for the past 21 years and biological data, We used density-independent and density-dependent Leslie Matrix models. Similar parameters were estimated from two models except that the density-dependent model was influenced by the density effect variable, q(i,t), The eigenvalue of the white croaker population for the $1984\~1995$ period was estimated to be 0.8, indicating a declining pattern of the population. The survival rate of 0-th year class was calculated to be 0.00005. Based on the schedule of the age-specific survival rate and fecundity, the future biomass and catch was predicted for various levels of fishing mortalities (F), If F was set at 0.252/yr ($F_{35x}$) or 0.368/yr ($F_{0.1}$), the biomass and catch increased, and if F was set at 0.922 ($F_{current}$), the biomass and catch decreased, The fishing mortality at equilibrium was estimated to be 0.7/yr. Finally, the management strategy of the white croaker was discussed.