• Korean Journal of Plant Resources
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• v.19 no.4
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• pp.447-458
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• 2006

The resource plants at the Manduksan and Mireukbong was listed 550 taxa: 107 families, 339 genera, 481 species, 1 subspecies, 65 varieties and 3 forms. Among 550 taxa listed was confirmed 323 taxa of edible plants (58.7%), 384 taxa of medicinal plants (69.8%), 267 taxa of ornamental plants (48.5%) and 268 taxa of the others (48.7%). Based on the list of the rare plants by the Forest Research Institute, 4 taxa were recorded in the studied areas; Lilium distichum (Preservation priority order: No. 159), Tricyrtis dilatata (No. 97), Aristolochia contorta (No. 151), Prunus yedoensis (No. 110) and based on the list of Korean endemic plants, 11 taxa were recorded; Cephalotaxus koreana, Carex okamotoi, Lilium amabile, Populus tomentiglandulosa, Salix purpurea var. japonica, Pseudostellaria multiflora, Prunus yedoensis, Forsythia koreana, Paulownia coreana, Weigela subsessilis, Aster koraiensis. Specific plant species by floral region were total 30 taxa; Prunus yedoensis in class V, Wistaria floribunda in class IV, 3 taxa (Spiraea salicifolia, Acer palmatum, Asperula lasiantha) in class III, 3 taxa (Potentilla dickinsii, Viola tokubuchiana var. takedana, Caryopteris incana) in class II, 22 taxa (Pinus koraiensis, Hosta capitata, Chloranthus japonicus, Salix glandulosa, Juglans mandshurica, etc.) in class I. This site needs urgent countermeasures, because there have increased many man-made damages like planting exotic plants, picking wild plants and soil compaction induced by human trampling.

• Geophysics and Geophysical Exploration
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• v.18 no.2
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• pp.64-73
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• 2015

Recently, hydraulic fracturing is used in various fields and microseismic monitoring is one of the best methods for judging where hydraulic fractures exist and how they are developing. When locating microseismic events using single vertical well data, distances from the vertical array and depths from the surface are generally decided using time differences between compressional (P) wave and shear (S) wave arrivals and azimuths are calculated using P wave hodogram analysis. However, in field data, it is sometimes hard to acquire P wave data which has smaller amplitude than S wave because microseismic data often have very low signal to noise (S/N) ratio. To overcome this problem, in this study, we developed a grid search algorithm which can find event location using all combinations of arrival times recorded at receivers. In addition, we introduced and analyzed the method which calculates azimuths using S wave. The tests of synthetic data show the inversion method using all combinations of arrival times and receivers can locate events without considering the origin time even using only single phase. In addition, the method can locate events with higher accuracy and has lower sensitivity on first arrival picking errors than conventional method. The method which calculates azimuths using S wave can provide reliable results when the dip between event and receiver is relatively small. However, this method shows the limitation when dip is greater than about $20^{\circ}$ in our model test.

• Journal of Korea Water Resources Association
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• v.39 no.2 s.163
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• pp.121-126
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• 2006

Snowmelt effect is identified from the analysis of the relationship between precipitation and groundwater level(GWL) data and Severe drawdown of GWL is observed in drought. Groundwater dam Operation Index (GOI), which is developed for the optimal operation of groundwater dam, is calculated by taking common logarithm of the moving average(MA) of precipitation data for a certain period. The period can vary from watershed to watershed because the period is decided by picking the maximum correlation coefficient between GWL and GOI of several MAs of precipitation. For Ssangchun watershed, the correlation was the strongest when we apply 70 day MA for GOI calculation. Snowmelt effect is considered by applying the temperature change by elevation($0.5^{\circ}C$ decrease per 100m) and examining the areal distribution of the watershed by elevation. Snow event is assumed when the daily average temperature is below $0^{\circ}C$ and snowmelt is assumed when the temperature is above zero degree Celsius. Total snowmelt is assumed for the day. When the snow event is occurred the precipitation data is separated into two components, snow and rainfall. The areal distribution by elevation is used for the calculation in the separation. The correlation between GWL and GOI is higher when we consider snowmelt effect than we neglected it.

• Journal of Biosystems Engineering
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• v.41 no.4
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• pp.281-287
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• 2016

Purpose: The purpose of this study is to develop a walking-type two-row sesame reaper, which can simultaneously perform the cutting and collecting of sesame plants and other crops like perilla and soybean. Methods: The factors involved in reaping sesame were determined experimentally in order to design a prototype of the sesame reaper. The prototype is made up of four parts for cutting, conveying, collecting, and running. The height of two disc-plate saw blades on the cutting part is adjusted by an adjusting wheel, and peripheral speed is adjusted in accordance with the running speed. The conveying belt of the conveying part can be tilted from $0^{\circ}$ to $90^{\circ}$. The collecting part extracts a predetermined amount of transferred sesame plants. The prototype was used to evaluate the performance at different working speeds, so that the work efficiency can be calculated. Results: The center of gravity of the sesame plants was 900 mm, measured from the end of the cut stem. The diameter of the disc-plate saw blade was determined to be 355 mm, peripheral speed was 20.4-32.7 m/s, and the picking height of the conveying belt for sesame was 130 mm. The performance of transfer and collection of the sesame, when the insertion angles were $60^{\circ}$ and $90^{\circ}$, proved to be excellent. However, when the angle was over $120^{\circ}$, the performance was only 75-80%. The performance was at 100% efficiency when the ratio between running speed and conveying belt speed of the prototype was 1:2, which seems to be the ideal ratio for the sesame reaper. Conclusions: A sesame reaper was developed, which can integrate the processes of cutting, conveying, and collecting, by investigating and considering various factors involved in the reaping process. The sesame reaper can reduce the costs for yielding and producing sesame due to its highly efficient performance.

• Journal of Gifted/Talented Education
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• v.20 no.3
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• pp.1005-1026
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• 2010

Here we live in a fast changing world. The information and communication technologies have been surprisingly developing and making progress of our society. One of the benefit about the information and communication technologies is an internet. We can't imagine our life without it and it finally ends up with causing internet addiction which is called side effect of it. Most of former studies were, however, about game addiction and psychological factors of indivisual. In fact, there was not enough studies about internet addiction of computer science gifted students. If we analize the difference between computer science gifted students and average students when it comes to factors of internet addiction, we would surely be able to find out the result which is very helpful for cause analysis and its remedy. This paper examined the risk and protection factors of the former studies and choose various factors through Delphi analysis by specialists of information and science gifted students. Comparative analysis of computer science gifted students and average students was done through the test tools. And picking up unique factors of computer science gifted students, this paper shows the implication that contributes to protection of internet addiction and its remedy.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2001.06a
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• pp.51-64
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• 2001

The qualities including taste of sweetpotato stored during the winter which can display in the spring market in Korea are affected by availability of storage for the roots. In order to make high storage availability of sweetpotato, the postharvest handlings should be done thoroughly from the moment of harvest until shipping them to the market. A lot of procedures that must be handled carefully for improving postharvest management are as follows; digging, trimming, gathering, putting in storage containers, carrying them from field to house, curing, storing, washing, drying, selecting marketable roots, packing and shipping to the market, etc.. Sweetpotatoes have a high moisture content, and a relatively thin and delicate skin, and are sensitive to chilling, so careless postharvest handling can lead to both quantitative and qualitative losses which may be extremely high in some circumstances. From now on research has concentrated on the improvement of postharvest conditions to increase yield and lower disease rates. Storage, which makes sweetpotatoes available through out the year, benefits both the producer and the consumer. Seven very important points must be needed in order to get the best quality marketable roots in the storing of sweetpotatos : $\circled1$The storage house must be clean and sanitary, $\circled2$The crop must be harvested before the first frost to avoid low-temperature injury, $\circled3$Particular care must be taken to avoid cutting, bruising, or other injuries of the sweetpotatoes during digging, picking up, grading, placing in containers, and moving to the storage house, $\circled4$Select sound, disease-free roots for storage $\circled5$Sweetpotatoes should be stored in properly stacked containers $\circled6$Cure immediately after harvest, preferably at 32∼33$^{\circ}C$ and 90 to 95 percent relative humidity for 4 to 7 days, After curing the temperature should be reduced to 13$^{\circ}C$ to 16$^{\circ}C$ by ventilating the storage with outside air. $\circled7$Store at 12$^{\circ}C$ to 14$^{\circ}C$ and a relative humidity of 80 to 85 percent. Storage houses should be located on suitable sites and should be tightly constructed and insulated so that temperature and humidity will be uniform. Sweetpotatoes are usually not washed and graded, and lately sometimes washed, graded, waxed, before being shipped to market. Consumer packaging of sweetpotatoes in paper boxes(10-15kg) or film bags is done mainly to aid marketing. The shelf life of washed roots in consumer packs in only 1 to 2 weeks. Weight loss of roots during marketing is much less in perforated film bags than in mesh and paper bags. Perforation of 0.8 to 1kg polyethylene bags with about six 6mm holes is essential ; to lower the internal relative humidity and avoid excessive sprouting, rooting, and dampness. Development and use of better postharvest handling with good storage facilities or marketing methods can minimize sweetpotate losses and has an effect of indirectly increasing productivity and farmer’s income.

• Journal of Ginseng Culture
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• v.1
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• pp.57-66
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• 2019

Ginseng has been recognized as a lifespan extending medicine which has been regarded as one of the medicines classified as top medicines, as the Boncho (medical herbs) study which is influenced by the idea of guidance's costume and food concept mainly in China is gaining its bona fide form. As the demand for ginseng has been expanded to other levels, the demand for ginseng has been increasing. Ginseng from the nature reached its supply chain limit due to its extinction and difficulty of picking, so it translated into ginseng cultivation of economy rather than harvesting in nature. After the start of ginseng cultivation, the ginseng cultivation was further enhanced by the rapid development of processing methods such as white-ginseng and red-ginseng, and the surge of consumption due to the traditional belief in ginseng drug efficacy and support of scientific research. In the Joseon Dynasty, the name Gasam (cultivated ginseng) had been created as ginseng was cultivated on farmland after the stage of SanYang (wild cultivated ginseng), the purpose of the new name Gasam is to differentiate from natural ginseng, and natural ginseng lost its firm position as the genuine ginseng as the Gasam replaced the genuine ginseng, and the natural ginseng got a new name of SanSam (wild ginseng). Because the real ginseng substance concept dissipated, and as Gasam is being called ginseng, the name Gasam was also disappeared. As a result, it was possible to grow large quantities according to the arrival of the Gasam era, and it was possible to supply the demand for ginseng, and it could become one agricultural industry. In this ginseng cultivation, in Japan where ginseng did not grow naturally, it was difficult to obtain ginseng from Joseon and faced with a shortage of ginseng at all times. Therefore, the shogun cultivated the Gasam systematically at the national level by the inside of the shogunate. However, since the natural ginseng is native to China and Korea, there is a concern about the deterioration of the quality of natural ginseng due to the incorporation of cultivated ginseng (Gasam). To protect the interests, the cultivation of ginseng was subject to control. For this reason, the lack of historical information on Gasam cultivation, which had to be started secretly, would be a natural result. In this paper, althouh not sufficient enough, the historical informations were used to summarize the history of ginseng cultivation in China, Japan and Korea.

• Korean Journal of Poultry Science
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• v.46 no.1
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• pp.11-15
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• 2019

The effects of red yeast rice powder on physicochemical properties of chicken thigh meat sausage were investigated. Control sausages were prepared with 1.2% NPS (nitrite pickling salt). Others samples were prepared with 1%, 2%, and 3% red yeast rice powder and 1.2% NaCl. With increasing red yeast rice powder content, the pH of uncooked and cooked samples generally decreased. In addition, lightness, and yellowness decreased with increasing content of red yeast powder (P<0.05), whilst redness increased with increasing content of red yeast powder in sausage samples (P<0.05). In addition, the samples with red rice powder showed more than 3 times higher redness compared to samples with 1.2% NPS, regardless of addition level. No significant difference in cooking yield among the treatments. The hardness of samples increased with increasing red yeast rice powder content, while the cohesiveness of samples containing red yeast rice powder was less than those observed for the control. Consequently, red yeast rice powder can be used to improve redness in sausages without adverse effect on cooking yield.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.4
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• pp.20-29
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• 2022

The operational modal analysis (OMA) technique, which extracts the modal parameters of a structural system using ambient vibrations, has been actively developed as a field of structural health monitoring of cable-supported bridges. In this paper, the short and long-term modal parameters of a cable-stayed bridge were evaluated using the acceleration data obtained from the two ambient vibration tests (AVTs) and three years of continuous measurements. A total of 27 vertical modes and 1 lateral mode in the range 0.1 ~ 2.5 Hz were extracted from the high-resolution AVTs which were conducted in the 6th and 19th years after its completion. Existing OMA methods such as Peak-Picking (PP), Eigensystem Realization Algorithm with Data Correlation (ERADC), Frequency Domain Decomposition (FDD) and Time Domain Decomposition (TDD) were applied for modal parameters extraction, and it was confirmed that there was no significant difference between the applied methods. From the correlation analysis between long-term natural frequencies and environmental factors, it was confirmed that temperature change is the dominant factor influencing natural frequency fluctuations. It was revealed that the decreased natural frequencies of the bridge were not due to changes in structural performance and integrity, but to the environmental effects caused by the temperature difference between the two AVTs. In addition, when the TDD technique is applied, the accuracy of extracted mode shapes is improved by adding a proposed algorithm that normalizes the sequence so that the autocorrelations at zero lag equal 1.

• Journal of Ginseng Culture
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• v.5
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• pp.1-20
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• 2023

In 1749, during an incident near the Tumen River in Hunchun, six people, all Qing ginseng pickers, were killed by seven Korean soldiers from the Chosŏn garrison. The Chosŏn soldiers encountered the ginseng pickers on the border and agreed to exchange goods, but when they failed to receive the proper price for rice, the soldiers became angry and decided to attack the Qing ginseng pickers. The seven Korean criminals were executed a year and a half after the incident. The whole process regarding the arrest and investigation of the criminals, as well as the official exchanges between the Qing and Chosŏn governments, were recorded in detail in the Chosŏn document written in Chinese and the Qing documents written in Manchu. In dealing with this murder case, the Qing local officials focused on identifying the murdered victims, clarifying the victims' responsibilities, and disposing of their remaining belongings. On the other hand, the Chosŏn government focused on providing reports quickly to the Qing officials about the investigation of the criminals. In doing so, it tried to reduce the risk of any possible problems that the murder case on the border could cause in its relations with the Qing government. The relevant records on this murder case show various aspects of the Qing and Chosŏn relations, including the contacts between the people along the Tumen River, border trespassing, material exchanges, rules about ginseng picking, and border patrols. This case also reveals that the Qing and Chosŏn people from various classes had different relationships depending on their respective interests.