• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.4
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• pp.247-254
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• 2004

The mesh selectivity of the drum net fish trap for elkhorn sculpin(Alcichthys alcicornis) in the estern sea of Korea was described. The selection curve for the elkhorn sculpin caught from the experiments between June 2003 and December 2003 was by SELECT(Share Each Length Class's Catch Total)model and by Kitahaa's method to a polynomial equation and two parameter logistic selection curve. The selection curve by SELECT model showed to be equal probability of entrance of the elkhorn sculpin in the large(55mm) and small(20mm) mesh traps by minimum AIC (Akaike Information Criteria). The equation of selectivity curve obtained by Kitahara's method using a logistic function with least square method was $s(R)\;=\;\frac{1}{1+exp(-0.3545R+2.141)$, where R=1/m, and/and m are total length and mesh size, respectively. The mesh selectivity curve showed that the current regulated mesh size(35mm) for the trap was corresponded to 21.4cm in the $L_{50}$of the selection curve for the elkhorn sculpin.

• Journal of Technologic Dentistry
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• v.30 no.2
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• pp.121-133
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• 2008

The purpose of this study was to evaluate the role of socioeconomic factors and health behaviors on the prevalence of oral diseases(dental caries and periodontal disease) among Korean adults. Data from the 2005 National Health and Nutrition Examination Survey was analyzed for adults aged over 19 years (n=25,215). Oral disease was defined as disease diagnosed by a dentist for the previous 12 months. Chi-square test and logistic regression analysis were used to conduct statistical analysis. The population without dental caries and periodontal diseases were used as the reference category for all analysis. The overall prevalence of annual dentist-diagnosed dental caries and periodontal diseases were 23.5% and 10.6% respectively. The relative risk of developing dental caries for graduates of middle school and lower were 1.53 times (95% CI: 1.24-1.89) more likely to develop dental caries comparing to college graduates. Low income earners were 1.23 times(95% CI: 1.01-1.49) more likely to develop dental caries than high income earners. Persons covered by national medical insurance were 1.45 times(95% CI: 1.08-1.95) more likely to develop dental caries comparing to persons covered by employee medical insurance. Compared with persons not eating snacks, the risk of developing caries in persons eating snacks once a day was 1.16(95% CI: 1.01-1.32), while those who snacked twice or more a day were 1.19(95% CI: 1.01-1.41). The relative risk of developing periodontal disease was 3.71(95% CI: 2.38-5.80) higher in older individuals than younger. In terms of education level, middle school graduates and lower were 1.54 times more likely to develop periodontal disease than college graduates. Low income earners were 1.47 times more likely to develop periodontal diseases than high income earners. Using data from a large, nationally representative sample of Korean populations, we support the hypothesis that the prevalence of oral diseases is related with socioeconomic factors and health behaviors. More intensive intervention efforts to reduce the prevalence of dental diseases are warranted in Korea.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.395-404
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• 2012

This study was conducted to develop site index equations and to estimate productive areas for major coniferous species in Korea such as Pinus densiflora Sieb. et. Zucc, Pinus densiflora for. erect, Larix leptolepis and Pinus koraiensis using environmental factors. Using the large data set from both a digital forest site map and a climatic map, a total of 43 environmental factors including 15 climatic variables were regressed on site index by tree species to develop site index equations. Six environmental factors by species were selected as independent variables in the final site index equations. The result showed that the coefficients of determination for site index equations by species were ranged from 0.36 to 0.56, which seem to be relatively low but good enough for the estimation of forest stand productivity. The site index equations developed in this study were also verified by three evaluation statistics such as the estimation bias of model, precision of model, and mean square error of measurement. According to the evaluation statistics, it was found that the site index equations by species fitted well to the test data sets with relatively low bias and variation. As a result, it was concluded that the site index equations by species were well capable of estimating site quality. Based on the site index equations, the productive areas by species for all forest areas were estimated by applying GIS technique to the digital forest site map and climate map. In addition, the distribution of productive areas by species was illustrated by using GIS technique.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.892-897
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• 2006

An experiment was designed to study the nutritional value of Chinese brown rice and maize for growing pigs. Six male grower pigs (Duroc${\times}$Landrace${\times}$Large White, $24.3{\pm}1.26$ kg average initial BW) were surgically fitted with a simple T-cannula at the terminal ileum and allotted within a $2{\times}2$ Latin square design. The pigs were fed either a maize or brown rice diet in a direct method to determine their digestibility. The brown rice used in this experiment was husked from one kind of early, long grain, and non-glutinous rice (ELGNR, indica rice: non-waxy rice, containing amylopectin and amylose) in southern China. Chromic oxide was used as a marker. The diets were supplied at about 4.0% of body weight in dry matter/d. Total faeces and urine were collected on days 4 and 5; digesta was collected on days 6-8 in each period. The average body weight was 24.3 kg at the start of the experiment and 27.6 kg at the end. The results showed that the apparent ileal digestibilities of most amino acids of brown rice were significantly higher than those in maize (p<0.01), as were the apparent ileal digestibilities of crude protein (CP), digestible energy (DE), organic matter (OM) and dry matter (DM) (p<0.05). However, the apparent ileal starch digestibilities of the two treatments were similar (p>0.05). The values of the apparent faecal digestibilities derived from the two methods, marker and total faecal-collection methods, were very similar and also correlated with each other. The difference in absolute value of the apparent faecal digestibilities between brown rice and maize was smaller compared to that of the apparent ileal digestibilities. The net protein utilization was higher (p = 0.07) and the DE metabolizable rate was significantly higher (p<0.01) for brown rice than for maize. The metabolizable energy (ME) of brown rice is similar to that of maize, while the DE of brown rice was relatively lower. It can be concluded that Chinese brown rice are better than maize not only in apparent ileal digestibilities, but also in metabolizable rate of amino acids and gross energy under the present study conditions.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.9
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• pp.1278-1284
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• 2000

An experiment was performed to evaluate different methods for preserving shrimp by-products and to determine their chemical composition. In the first experiment three ratios of shrimp by-product (SBP) to molasses (6:1, 4:1 and 3:1, wet weight), and to cassava root meal (3:1, 2:1 and 1:1, wet weight of shrimp by-product and air-dry weight of cassava root meal) were investigated. The pH of the SBP ensiled with molasses at a ratio of 3:1, and with cassava root meal at a ratio of 1:1, decreased during the first week to below 4.5 and remained low up to day 56 of ensiling, whereas the pH of the mixtures with higher ratios of SBP remained above 7.0, and the material deteriorated rapidly. The dry matter decreased initially in all treatments but then increased slightly from day 28 in the treatment where shrimp by-product was ensiled with cassava root meal at a ratio of 1:1. The crude protein (CP) and ammonia-N $(NH_3-N)$ contents of the preserved shrimp by-product material ensiled with molasses at a ratio of 3:1 increased significantly one week after ensiling. The CP content then remained constant, while the $NH_3-N$ concentration continued to increase up to 56 days after ensiling. When SBP was ensiled with cassava root meal at a ratio of 1:1 the CP content of the silage increased significantly up to 21 days after ensiling and then decreased back to the original level after 56 days, whereas $NH_3-N$ increased markedly up to 14 days and then remained fairly constant up to 56 days. However, the $NH_3-N$ content was significantly higher when SBP was ensiled with cassava root meal than with molasses. A balance experiment was carried out, arranged as a double Latin-square and including 6 F1 (Large White ${\times}$ Mong Cai) castrates fed randomly one of three diets based on cassava root meal, rice bran, and fish meal (FM) or shrimp by-product ensiled with molasses (SBEMO) or with cassava root meal (SBECA) as the main protein source. Apparent organic matter and CP digestibilities were significantly (p<0.001) higher for the fish meal diet than for the two shrimp by-product diets, although CP digestibility in SBEMO and SBECA was similar (p>0.05). N-retention was significantly higher for the fish meal diet than for the SBEMO diet, which in turn was significantly higher than for the SBECA diet (p<0.01). It can be concluded that shrimp by-product can be preserved by ensiling with molasses at a ratio of 3:1 or with cassava root meal at a ratio of 1:1. Nutrient digestibility and N-retention of diets based on these shrimp by-product silages were lower than for similar diets based on fish meal, probably due to their high chitin content and inferior amino acid balance.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.347-355
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• 2006

A study was conducted to predict the rumen microbial protein production based on urinary excretion of purine derivatives in buffaloes fed a diet of wheat straw and concentrate (40:60) at four fixed levels of feed intake. (95, 80, 60 and 40% of preliminary voluntary feed intake) following experimental protocol of IAEA (Phase I). The buffaloes were allocated according to a $4{\times}4$ latin square design. The urinary allantoin, uric acid, total PD excretion (mmol/d) in treatments L-95, L-80, L-60 and L-40 was 20.13, 16.00, 12.96 and 9.17; 1.88, 2.12, 2.11 and 2.15; 22.01, 18.12, 15.07 and 11.32, respectively and were significantly (p<0.05) different among treatments except for uric acid. The rate of PD excretion (mmol/d) was positively correlated with the digestible organic matter intake. Variations were observed in PD and creatinine concentration in spot samples collected at 6-hour interval. However, daily PD:Creatinine ratio (PDC index) appears to be a reasonably good predictor of microbial-N supply. The contribution of basal purine excretion to total excretion of purine derivatives (PD) was determined in pre-fasting period followed by a fasting period of 6 d (Phase II). Daily PD and creatinine excretion (mmol/kg $W^{0.75}$) during fasting averaged 0.117 and 0.456 respectively for buffaloes. The excretion rates of PD decreased significantly (p<0.01) during fasting compare to pre-fasting period, the urinary creatinine excretion remained almost similar. Except for creatinine, plasma concentration of target parameters significantly (p<0.01) declined during fasting. Likewise, glomerular filtration rate (GFR) and renal clearance of allantoin and uric acid also decreased. Based on the PD excretion rates during fasting and at different levels of feed intake obtained in this study, a relationship between daily urinary PD excretion (Y-mmol) and microbial purine absorption (X-mmol) was developed for buffaloes as Y = 0.74X+0.117 kg $W^{0.75}$. The microbial N supply (g/kg DOMI) remained statistically similar irrespective of dietary treatment. The results showed that excretion of urinary purine derivatives is positively correlated with the levels of feed intake in Murrah buffaloes and thus, estimation of urinary purine derivatives and PDC index could be used to determine microbial nitrogen supply when there is large variation in level of feed intake.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.2
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• pp.55-63
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• 2017

Crowdfunding recently receives a great deal of attentions as an alternative finance for small and medium-sized enterprises or business ventures that suffer from financial constraints. Crowdfunding is a new form of platform that enables a large number of people to invest a small amount of money for promising new business items directly. We analyzed the effect of type, period, method of projects on crowdfunding outcomes. We measure the outcome in terms of the ratio of the collected to the target amount. We collected data from three Korean crowdfunding platform companies, and the data consisted of 239 projects from 2012 to 2014. We use both logit and ordinary least square method for evaluation. Generally, the amount of target itself has no effect on the outcome. Equity crowdfunding shows higher success rate and better outcome than rewards crowdfunding. All or Nothing method leads to the higher ratio of the collected to the target amount than Keep It All. There is an inverted U-shape between the number of investors and the ratio of the collected to the target amount. Finally, the ratio of the collected to the target amount is decreasing in a crowdfunding period.

• Journal of Korea Water Resources Association
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• v.49 no.5
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• pp.423-429
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• 2016

This study aims at assessing the quality of the Advanced Microwave Scanning Radiometer 2 (AMSR2) soil moisture products onboard GCOM-W1 satellite based on Land Parameter Retrieval Model (LPRM) soil moisture retrieval algorithm with field measurements in South Korea from March to September, 2014. Results of mean bias and root mean square error between AMSR2 LPRM soil moisture products (X-band) and ground measurements showed reasonable value of 0.03 and 0.16. Also, the maximum of the Pearson correlation coefficients was 0.67, which showed good agreement in terms of temporal variability with ground measurements. By comparing AMSR2 soil moisture with in-situ measurement according to the overpass time and band frequency, X-band products on the ascending time outperformed than those of C1-band and C2-band. Furthermore, this study offers an insight into the applicability of the AMSR2 soil moisture products for monitoring various natural disasters at a large scale such as drought and flood.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.518-527
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• 2020

The establishment of a green remodeling strategy is focused on technology, so the necessity of establishing a customized strategy considering the field situation has emerged. This paper examined the technology strategy through sensitivity analysis as a methodology for guiding strategy. For a 90-square-meter detached house, nine models of the construction standards of pre-1980s, 1984, and 2010 in Seoul, Daejeon, and Busan were assessed using the optimization method that combines the energy plus engine and the ModeFrontier. Sensitivity analysis was performed, and the remodeling strategy priority was derived. For pre-1980 models, the strategy for enhancing the roof insulation performance had a significant priority. The SHGC values of the windows were found to have the next highest priority regardless of the region and the time of completion, showing that the performance standard, including the SHGC, needs to be expanded. The possibility of remodeling while maintaining the existing geometry was confirmed because the adjustment of the window wall ratio accompanying large-scale demolition works has low priority. The priorities of technology strategies in each case showed very different patterns, suggesting the possibility of establishing a remodeling strategy by a comprehensive evaluation along with economics and constructability analysis.

• Korean Journal of Cognitive Science
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• v.31 no.1
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• pp.1-23
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• 2020

This paper introduces SNUDM, an analysis program for Ratcliff's diffusion model, which has been one of the most important models in cognitive psychology over the past 35 years and which has come to occupy an important place in cognitive neuroscience in recent years. The analysis tool is designed with the basic principles of easy comprehension and simplicity in use. A diffusion process was programmed as the limit of a simple random walk in a manner resembling Ratcliff & Tuerlinckx(2002). The response time distribution of the model was constructed by simulating the time taken by a random walk until it reaches a threshold with small steps. The optimal parameter values in the model are found to be the smallest value of the chi-square values obtained by comparing the resulting distribution and the experimental data using Simplex method. For simplicity and ease of use, the input file used here is created as a file containing the quantile of the reaction time, the trials and other information. The number of participants and the number of conditions required for such work programs are given in a way that answers the question. Using this analysis tool, the experimental data of Ratcliff, Gomez, & McKoon(2004) were analyzed. We found the very similar pattern of parameter values to Ratcliff et al.(2004) found. When comparing DMAT, fast-dm and SNUDM with the generated data, we found that when the number of trials is small, SNUDM estimates the boundary parameter to a value similar to fast-dm and less than the DMAT. In addition, when the number of trials was large, it was confirmed that all three tools estimate parameters similarly.