• Journal of the Economic Geographical Society of Korea
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• v.21 no.1
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• pp.20-33
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• 2018

Population distribution in urban space varies with transportation flow changing along time of day. Transportation flow is directly affected by the activities of urbanites and the distribution of related facilities, since the flow is the result of moving to the point where the facilities associated with their activities are located. It is thus necessary to analyze the spatio-temporal characteristics of the urban population distribution by integrating the distribution of activity spaces related to the daily life of urbanites and the flow of transportation. The purpose of this study is to analyze the population distribution in urban space with daily and weekly time bases using the building database and T-card database in the city of Seoul, which is rich in information on land use and transportation flow. For a time-based analysis that is difficult to grasp by general statistical techniques, a four-dimensional visualization method combining time and space using a Java program is devised. Dynamic visualization in the four-dimensional space and time allows intuitive analysis and makes it possible to understand more effectively the spatio-temporal characteristics of population distribution. For this purpose, buildings are classified into three activity groups: residential, working, and commercial according to their purpose, and the number of passengers traveling to and from each stop site of bus and subway networks in the T-card database for one week is calculated in one-minute increments, Visualizing these and integrating transportation and land use, we analyze spatio-temporal characteristics of the population distribution in Seoul. As a result, it is found that the population distribution of Seoul displays distinct spatio-temporal characteristics according to land use. In particular, there is a clear difference in the population distribution pattern along the time axis according to the mixed aspects of working, commercial, and residential activities. The results of this study can be very useful for transportation and location planning of city facilities.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.2
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• pp.157-164
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• 2012

This experiment was conducted to investigate an optimum harvest time for hairy vetch (HV) seed production. The seeds were harvested at 5 times, 35, 42, 48, 54, and 58 days after flowering (DAF) in 2009 and 2010. In 2011, 3 times of harvest, 39, 49, and 53 DAF were done at Suwon, middle part of Korea. HV plants were harvested and threshed by manually at each time. Seed yield, yield components, germination rate, hard seed rate, and viviparous germination rate were investigated. The highest seed yield represented 54 DAF in 2009, 42 DAF in 2010, and 49 DAF in 2011. When the triticale, HV support plant, comes to early lodging, the time of highest yield was delayed. 1,000-seed weight linearly increased from 35 DAF to 54 DAF. The later harvested seed showed a trend of increasing germination and hard seed ratio. However, viviparous germination had occurred because of in rainy season. In conclusion, it was presumed that an optimum harvest time for safe seed production in HV should be during 42 DAF ~ 54 DAF before the rainy season considering seed yield, 1,000-seed weight and germination.

• Journal of the Korean Electrochemical Society
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• v.10 no.1
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• pp.25-30
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• 2007

Proton exchange membrane fuel cell(PEMFC) performance could be affected by various factors such as cell temperature, total pressure, partial pressure of reactants and relative humidity. Hydrogen ion is combined with water to form hydronium ion [$H_3O^+$] and pass through membrane resulting electricity generation. Cooling system is needed to remove heat and other uses on large scale fuel cell. In case that collant conductivity is increased, fuel cell performance could be decreased because produced electricity could be leaked through coolant. In this study, triple distilled water(TDW) and antifreeze solution containing ethylene glycol was used to observe resistance change. Resistance of TDW was taken 28 days to reach preset value, and effect on fuel cell operation was not observed. Resistance of antifreeze solution was not reached to preset value up to 48 days, but performance failure occurred presumably caused by bipolar plate junction resulting stoppage resistance experiment. Generally PEMFC humidification is performed near-saturated operating conditions at various temperatures and pressures, but non-humidifying condition could be applied in small scale fuel cell to improve efficiency and reduce system cost. However, it was difficult to operate large scale fuel cell without humidifying, especially higher than $50{\sim}60^{\circ}C$. In case of small flux such as 0.78 L/min, temperature difference between inlet and outlet was occurred larger than other cases resulting performance decrease. Non-humidifying performance experiments were done at various cell temperature. When both of anode and cathode humidification were removed, cell performance was strongly depended on cell operating temperature.

• Food Science and Preservation
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• v.23 no.6
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• pp.811-818
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• 2016

The purpose of this study was to investigate changes in the amino acid content and physicochemical properties of Cheonggukjang prepared by using various soybean cultivars (Daewon, Deapung, Seadanbeak, and Taekwang) and a functional microorganism (Bacillus subtilis HJ18-9). These soybeans were conventional Cheonggukjang (control) and Cheonggukjang fermented with Bacillus subtilis HJ18-9 (treated). The moisture contents of steamed, control, and treated soybean were 62.45~67.12%, 63.28~67.14%, and 64.50~66.87%; amino-type nitrogen contents were 6.53~24.25 mg%, 27.63~122.09 mg%, and 37.29~133.48 mg%; and ammonia-type nitrogen contents were 26.92~47.95 mg%, 45.45~156.36 mg%, and 28.02~121.13 mg%, respectively. The umami taste associated with several amino acids (aspartic acid and glutamic acid) in Cheonggukjang was lower than that for steamed soybeans, while the bitter taste from amino acids (methionine, valine, isoleucine, leucine, and phenylalanine) was higher than that for steamed soybeans. The result of sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that the molecular weight of steamed soybeans was less than 100 kDa, while control and treated groups showed low molecular weights below 34 kDa, confirming their protein hydrolysis to small molecular weight. These results are information for developing functional fermented soybean paste and diversification using soybean cultivars.

• Korean Journal of Plant Resources
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• v.29 no.1
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• pp.62-89
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• 2016

The great part of the traditional knowledge on ethnobotanical plants and their uses is gradually vanishing due to industrialization, therefore ethnobotanical studies that explore and preserve the knowledge are in urgent needed before the knowledge are lost ever. This study was conducted to record and conserve the traditional knowledge of botanical taxa in Korea from 2006 to 2014. According to the survey results, derived from 17,328 sheets of 1,771 residents at 868 places, the ethnobotanical plants in Korea consisted of a total 924 taxa; 130 families, 493 genera, 813 species, 7 subspecies, 92 varieties and 12 form. Of them, herbs were 619 taxa (67.0%) and woody plants were 305 taxa (33.0%). 707 taxa (76.5%) out of 924 taxa grow wild, 44 taxa (4.8%) were cultivated wild species, 145 taxa (15.7%) were introduced for cultivation, and 28 taxa (3.0%) were naturalized plants. The analysis of usage for 924 taxa showed that the edible use was the highest with 58.9%, followed by medicinal with 26.9%, material with 3.7% and ornamental with 2.3%, respectively. The leaf of plant was the most useful part, followed by stem and root. Quantitative analysis of the ethnobotanical plants in Korea was performed by the basic values of FC, NU and UR, and indices of CI, RFC, RI and CV. As a result, The CI place Artemisia princeps in first position, followed by Aster scaber, Kalopanax septemlobus. The RFC place A. scaber in first position, followed by A. princeps, Aralia elata. The RI place A. princeps in first position, followed by Pinus densiflora, Morus alba. The CV place A. princeps in first position, followed by P. densiflora, K. septemlobus.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.780-786
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• 2009

To develop a novel application for roasted ground coffee residue, hot water extract of roasted ground coffee residue was used in manufacturing salted mackerels. First, DPPH radical scavenging effect of roasted ground coffee residue extract was measured. As a result, roasted ground coffee residue extract showed high activity of about 92% in the concentration of 0.4 to 4 mg/mL. Thereafter, the salted mackerel was treated with 5, 10 and 15% of roasted ground coffee residue extract and its shelf-life and quality was investigated. The salted mackerels treated with 15% roasted ground coffee residue extract showed significantly low TBARS and VBN as compared to the control. In sensory evaluation, the salted mackerels treated with 10 and 15% roasted ground coffee residue extracts scored higher as compared to the control. In conclusion, roasted ground coffee residue extract increased the shelf-life of salted mackerel and improved the sensual quality by inhibiting lipid oxidation.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.28-39
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• 2017

The purpose of this study was to analyze the tendencies of the written test questions regarding the scientific plant names in the subject of scenic planting in the national qualification test for landscape engineers. To achieve this purpose, targeting the 20 questions in the subject of scenic planting, the study chronologically analyzed the types of the presented questions about the scientific names of the plants, the changes in their year-to-year number, and their presentation frequency over the past 11 years from 2006 to 2016. The following was found by an analysis of the tendency of the questions presented over 11 years from 2006 to 2016 regarding the scientific plant names in scenic planting in the written test of the national technical qualification examination for landscape engineers. The number of these questions was 234, and they were classified into 13 items: scientific names, families/genuses/ species, characteristics, barks, roots, foliage, flowers, fruits, properties, places of origin, stalks, leave, and uses. After analyzing the examination question trends per year, the year in which the highest number of questions was given was 2013 at 56.6%; the ratio of questions asking botanical names increased until 2013, although that ratio decreased starting in 2014 due to consistent efforts from the landscaping field. The plant species most frequently asked about were Betula platyphylla and Taxus cuspidata and others frequently asked about included Pinus densiflora, Acer palmatum, Forsythia koreana, Cercis chinensis, Robinia pseudoacacia, Cornus officinalis, Zelkova serrata, Abies holophylla, Camellia japonica, Sophora japonica, Chaenomeles sinensis, which were asked about more than 10 times. The number of plant species presented as question items or choice items was 240 and their presentation frequency was 806, Among these, 66 species were steadily presented more than five times. They were presented 486 times, accounting for 27.5% of all species. The number of the new plant species which began to be presented in 2009 were 119(49.58% including Quercus myrsinaefolia) of all 240 species, indicating that their presentation frequency was gradually increased. As a result of comparative analysis of questions on arbor and shrub, evergreen and leaf abscission that have been presented for recent 11 years, the questions on arbor were more than shrub, the questions on leaf abscission were more than evergreen.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.47-56
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• 2020

In this study, three levels of W/B(Water to Binder) ratio (0.37, 0.42, 0.47) and substitution ratio of GGBFS (Ground Granulated Blast Furnace Slag) rate (0 %, 30 %, 50 %) were considered to perform RCPT (Rapid Chloride Diffusion Test) at the 1,095 aged day. Accelerated chloride diffusion coefficient and passed charge of each concrete mixture were assessed according to Tang's method and ASTM C 1202, and improving behaviors of durability performance with increasing aged days are analyzed based on the test results of previous aged days from the preceding study. As the age of concrete increases, the passed charge and diffusion coefficient have been significantly reduced, and especially the concrete specimens containing GGBFS showed a significantly more reduction than OPC(Ordinary Portland Cement) concrete specimen by latent hydraulic activity. In the case of OPC concrete's results of passed charge, at the 1,095 days, two of them were still in the "Moderate" class. So, if only OPC is used as the binder of concrete, the resistance performance for chloride attack is weak. In this study, the time-parameters (m) were derived based on the results of the accelerated chloride diffusion coefficient, and the deterministic and probabilistic analysis for service life were performed by assuming the design variable as a probability function. For probabilistic service life analysis, durability failure probabilities were calculated using Monte Carlo Simulation (MCS) to evaluate service life. The service life of probabilistic method were lower than that of deterministic method, since the target value of PDF (Probability of Durability Failure) was set very low at 10 %. If the target value of PDF suitable for the purpose of using structure can be set and proper variability can be considered for each design variable, it is believed that more economical durability design can be made.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.225-233
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• 2019

This study was conduct to investigate the effect of mixed seed sowing and flour blending on the uniformity of flour quality of Korean domestic wheat. Two wheat varieties (Keumkang and Baegjoong) were selected for sowing mixed seeds, and their growth characteristics and flour quality were analyzed. Quality of flour blending with the same varieties was also evaluated. The ratios for mixed seed sowing and flour blending were from 0 to 100% with a 10% increase of interval for each treatment. On increasing the portion of Baegjoong in mixed seed sowing, the heading time was a little delayed, however, yield increased. The results of the flour quality showed lower damaged starch content and sodium carbonate SRC (solvent retention capacity) value for Keumkang than for Baegjoong. Protein quantity by protein content and quality by SDSS (Sodium Dodecyle Sulfate-Sedimentation) volume, lactic acid SRC, and mixograph pattern of Keumkang were superior to those of Baegjoong. Compared with mixed seed sowing, overall quality characteristics of flours with different ratios showed predictable and proportional change by flour blending. This demonstrated the successful application of flour blending, compared with mixed seed sowing, for improving the uniformity of flour quality.

• Korean Journal of Food Science and Technology
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• v.53 no.5
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• pp.607-612
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• 2021

This study investigated the seed and water absorption characteristics of red bean cultivars in Korea. The length and width of all seeds were 7.74-8.99 mm and 5.33-5.54 mm, respectively. The hilum lengths and widths were 3.21-4.01 mm and 0.58-0.73 mm, respectively. The weight of 100 seeds was 12.14-20.21 g, and the seed coat thickness of red beans ranged from 39.18-50.01 mm. During soaking for 30 h, red beans exhibited a lag phase in the initial soaking time, followed by a rapid absorption phase, and finally contained more than 130% moisture. When water absorption was applied to the sigmoid equation, the curve fitting exhibited a high R², and the kinetics of water absorption were 0.202-0.715 h^-1, which differed among varieties. Pearson's correlation of hilum width (r=0.7858^*) and seed thickness (r= -0.9954^***) exhibited strong correlations with water absorption, suggesting that these are important factors in red bean processing.