• Journal of Plant Biology
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• v.19 no.3
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• pp.85-91
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• 1976

A comparison betwen the productivity of Pinus rigida which is native in the Eastern United States, and P. rigitaeda which is F1 hybrid between P. rigida and P. taeda, has been established. For each tree the diameter at breast height (D) and the height of tree (H) were measured in three years. The standard sample trees were down and then weighed each organ. From obtained data the allometric relation between $D_2H$ and dry weight of the trunk (Ws), the branches (Wb) and the leaves (Wl) of P. rigida were approxmated by $$Ws=0.0592 (D^2H)^{0.837}$$ $$Wb=0.0065 (D^2H)^{0.989}$$ $$Wl=0.0447(D^2H)^{0.690}$$ and those of P. rigitaeda were approximated by $$Ws=0.0522 (D^2H)^{0.843}$$ $$Wb=0.0037 (D^2H)^{1.117}$$ $$Wl=0.0207 (D^2H)^{0.856}$$ From the above, the standing crops of above ground of P. rigida were estimated to be as much as 16.93-34.35 ton dry matter per ha, and those of P. rigitaeda were 20.45-45.55 ton per ha. Annual net production was appraised at 8.07-9.35 ton/ha.yr in P. rigida and at 11.59-13.41 ton/ha.yr in P. rigitaeda (1.0:1.4). It is assumed that high productivity of P. rigitaeda stand compared with P. rigida resulted from an increase of the leaf amount with age. Photosynthetic ability under the saturated light of the current and theold leaves of P. rigida were respectively 2.62 and 0.66mg CO2/g. d. wt..hr and those of P. rigitaeda were 1.17 and 0.96mg CO2/g.d. wt.hr. Respiration of the current and the old leaves at $25^{\circ}C$ were 1.00 and 0.90 mg CO2/g. d. wt..hr. in P. rigida and 0.90 and 0.45mg CO2/g.d.wt.hr in P. rigitaeda. It is assumed that photosynthetic longevity of P. rigitaeda leaves was vigorously maintained longer than that of P. rigida.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.419-429
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• 2022

American ginseng (Panax quinquefolium L.) is a perennial herbaceous plant widely cultivated in China, Korea, the United States, and Japan due to its multifunctional properties. In northwest China, transplanting after 2-3 years has become the main mode of artificial cultivation of American ginseng. However, the effects of the cultivation process on the chemical properties of the soil and bacterial community remain poorly understood. Hence, in the present study, high-throughput sequencing and soil chemical analyses were applied to investigate the differences between bacterial communities and nutrition driver factors in the soil during the cultivation of American ginseng. The responses of soil nutrition in different ecological niches were also determined with the results indicating that the cultivation of American ginseng significantly increased the soluble nutrients in the soil. Moreover, the bacterial diversity fluctuated with cultivation years, and 4-year-old ginseng roots had low bacterial diversity and evenness. In the first two years of cultivation, the bacterial community was more sensitive to soil nutrition compared to the last two years. Proteobacteria, Actinobacteria, Gemmatimonadetes, Acidobacteria, Firmicutes, and Bacteroidetes dominated the bacterial community regardless of the cultivation year and ecological niche. With the increase of cultivation years, the assembly of bacterial communities changed from stochastic to deterministic processes. The high abundance of Sphingobium, Novosphingobium, and Rhizorhabdus enriched in 4-years-old ginseng roots was mainly associated with variations in the available potassium (AK), total phosphorus (TP), total potassium (TK), and organic matter (OM).

• Korean System Dynamics Review
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• v.13 no.3
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• pp.47-66
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• 2012

This paper aims at investigating and identifying the factor that has led the back and forth relationship between China and the United States since 1989. Previous studies on this subject addressed the issue by taking either of two approaches: one with the micro view that interprets the back and forth relationship in the context of the end of the Cold war, on other hand, with the macro view that interprets the fragile relationship in the context of the rise of China. However, neither of the approaches explains with sufficiency the question at hand. Hence for the inquiry, this article suggests a fresh view by exploring alternative method of using a cognitive map of each nation's leader, Jiangzemin and Bill Clinton. This article provides an empirical analysis through the Selected works of Jiangzemin and the speeches of Bill Clinton in 1998 for the first time in the field of Sino-US relationship studies in Korea. With the results of the cognitive map analysis, we can reach the following four points. Firstly, indicators of the forth relationship between China and the US are: i) the recognition by Bill Clinton on the importance of China's economic growth and; ii) the US's cooperation of science technology with China. Second, the conflict between China and the US results from the discordance of opinions on the matter of human rights and military power. Second, the conflict will inevitably arise on environmental issues around the globe including a global warming. Third, while China has yet to find a legitimate reason to agree upon these issues with the US, the US urges China of its cooperation. Lastly, Both China and the US attach great importance to the alliance with Japan. This implicates that relatively, issues involving Japan take more control in the China-US relationship, than those of Korea Peninsula.

• Journal of the Korean Chemical Society
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• v.47 no.6
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• pp.625-632
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• 2003

In this study, the effects of two types of reward methods in cooperative learning were investigated upon students' achievement, learning motivation, perceptions of learning environment and perceptions of reward methods. Seventh graders (N=61) were selected from a co-ed middle school in Seoul, and were taught about 'three states of matter', 'motion of molecules' and 'change of state and thermal energy' for 14 class hours. Reward methods were classified into task-oriented reward and performance-oriented reward. The results revealed that high-level students performed better in the task-oriented reward group, and low-level students performed better in the performance-reward group for the 'application' subcategory of the achievement test. The scores of attention and relevance in learning motivation and task orientation, involvement, and order and organization in perceptions of learning environment test were significantly higher in the task-oriented reward group than those in the performance-oriented reward group.

• Economic and Environmental Geology
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• v.31 no.4
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• pp.291-296
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• 1998

Pedogenic hematite is a well known agent for sink of pollutants and nutrients and for aggregation of particles in soils. Changes in physical and chemical properties of two sandy loam soils (Anahuac and Crowley soils) from the Southern Coastal Plain, the United States of America, were tested after adding finely ground crystalline hematite prepared for drilling fluid weighting material. There was an increase in hydraulic conductivity (HC) of the soils with addition of up to 3% by weight of hematite but a decrease in HC with addition of more hematite. The aggregate stability (AS) of the soils was not affected by adding hematite. Anahuac soil with higher content of organic matter and lower sodium adsorption ratio (SAR) had higher values of HC and AS than Crowley soil. Adding hematite also resulted in a slight increase in zinc (Zn) adsorption by the soils, but had no influence on the adsorption of phosphate.

• Journal of People, Plants, and Environment
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• v.24 no.6
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• pp.585-593
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• 2021

Background and objective: Illegal open-air incineration, which is criticized as a leading source of air pollutants among agricultural activities, currently requires constant effort and attention. Countries around the world have been undertaking studies on the emission of heavy metal substances in fine dust discharged during the incineration process. A precise analytical method is required to examine the harmful effects of particulate pollutants on the human body. Methods: In order to simulate open-air incineration, the infrastructure needed for incineration tests complying with the United States Environmental Protection Agency (EPA) Method 5G was built, and a large-area analysis was conducted on particulate pollutants through automated scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDS). For the test specimen, high-density polyethylene (HDPE) waste collected by the DangJin Office located in Choongcheongnam-do was used. To increase the identifiability of the analyzed particles, the incineration experiment was conducted in an incinerator three times after dividing the film waste into 200 g specimens. Results: Among the metal particulate matters detected in the HDPE waste incineration test, transition metals included C (20.8-37.1 wt%) and O (33.7-37.9 wt%). As for other chemical matters, the analysis showed that metal particulate matters such as metalloids, alkali metals, alkaline earth metals, and transition metals reacted to C and C-O. Si, a representative metalloid, was detected at 14.8-20.8 wt%, showing the highest weight ratio except for C and O. Conclusion: In this study, the detection of metal chemicals in incinerated particulate matters was effectively confirmed through SEM-EDS. The results of this study verified that HDPE waste adsorbs metal chemicals originating from soil due to its own properties and deterioration, and that when incinerated, it emits particulate matters containing transition metals and other metals that contribute to the excessive production and reduction of reactive oxygen species.

• Journal of Biomedical Engineering Research
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• v.36 no.5
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• pp.150-154
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• 2015

Long time ultrasound scan can cause a temperature rise in human tissue and affect the physical body. This is closely connected with patients' safety. So many researchers have been studied on this matter with animals such as mammals and experimental rat, because diagnostic ultrasound has been used many types of human organ to find disease. Therefore, this study is tested on bean sprouts to search how far the tissue temperature changes because of the excessive scanning consequence from ultrasound diagnosis and frequent number of ultrasonic scanning and how much affect their growth. The United States and several European countries have restrictions for number of scanning, while South Korea does not have any limitation for using ultrasound diagnosis. Comparison was that how different condition affect its' growing. The testing group is like many pregnancy moms to have 50 minutes in B-mode and color doppler mode by linear, convex and sector probe every day for a week and the other is to scan only once during the testing period. As a result, it was confirmed that there was a significant growing difference on frequent ultrasonic scanning group compared to normal one. So the final conclusion is that there needs to have a significant limitation of ultrasound scan time and a number of inspection when having for diagnostic ultrasound and recommendation like USA and a few European countries.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.53
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• pp.49-74
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• 2012

This study primarily concerns the seller's right to require performance under the United Nations Convention on International Sale of Goods(1980) (here-in-after the CISG). By virtue of art. 62 of the CISG, the seller may require to pay the purchase price, take delivery or perform his other obligations. The right is known as a process whereby the aggrieved seller obtains as nearly as possible the actual subject-matter of his bargain, as opposed to compensation in money for failing to obtain it. The study describes and analyzes the provisions of the CISG as to the seller's right to require performance, focusing on the questions of what the seller can require the buyer to perform, and what the restrictions of his right to require performance are. It particularly deals with main controversial issues among scholars as to whether art. 28 of the CISG is applied to the seller's action for the price and so that it opens the door domestic traditions and national preconditions that prevent judges and enforcement authorities in some contracting states, and whether the seller's to require performance is subject to the duty to mitigate loss within the meaning of art. 77 of the CISG. On the basis of the analysis, the study puts forward the author's arguments criticizing various the existing scholars' views. In addition, this study provides legal and practical advice to the contracting parties when it is expected that the CISG is applicable as the governing law.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.628-633
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• 2010

All the text of housing in 1910s was conveyed in three; hygiene general readings, home economics texts saying women's responsibility of cleaning house, and Japanese's observation and criticizing Korean housing. It stressed sanitary conditions of housing and criticised Korean housing dirty, of which contents and logic were same with the housing discourse in 1900s but much simpler and smaller in amount. It was mainly written by those in medical treatment field like doctors for enlightenment of private hygiene practice to Koreans. Because Choson Government-General(朝鮮總督府) excluded Korean residental areas from urban sanitation project, they remained dirty in 1910s. The practice of housing sanitation remained just as a matter of private sanitary practice. These political and discoursive conditions insinuated a sense that Korean dirty housing was representation of Korean's uncivilized customs and manners and a reason for being colonized. This sense made many Koreans to insist their housings' reforming to sanitary states just for civilization during colonized period.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1651-1664
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• 2013

Precise analysis on deterioration processes of road pavements is not so simple matter due to severe uncertainty originated from a lot of explanatory variables engaged in. For those reasons, most analytical models for pavement deterioration prediction have often preferred to probabilistic approaches than deterministic models. However, the general probabilistic approaches that treat overall characteristics of population or entire sample would not be suitable for providing detail or localized information on their changing process. Considering the aspects, this paper aimed to suggest a stochastic disaggregation method to analyze the localized deterioration speeds and its variances changed by time and condition states. In addition, life expectancies and their uncertainty were estimated by probabilistic algorithm using the disaggregated stochastic process. For an empirical study, pavement inspection data (crack) accumulated from 2003 to 2010 from Korean national highway network was applied. This study can contribute to securing reliability of life cycle cost analysis, which is one of the primary analyses in road asset management, with much advanced deterioration forecasting functions. In addition, it would be meaningful trials as fundamental research for preventive maintenance strategy that demands essential understanding on changing process of the deterioration speed of pavement.