• Korean Journal of Environment and Ecology
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• v.35 no.3
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• pp.237-255
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• 2021

Lychnis wilfordii (Regel) Maxim. is one of the wetland specialists mainly distributed in peatlands at high latitudes. In Korea, it is isolated in two regions. This study investigated habitats, growth traits, and self-compatibility of L. wilfordii and assessed the internal dynamics of its population persistence. Its population has remained stable in the Yongneup Wetland Protected Area (YWPA). There was a clear difference in vegetation environment between YWPA and the distribution area in Daegwallyeong (DWL), Pyeongchang-gun. It has self-compatibility while pollinators facilitate its seed production. It produces a large number of hibernacles and bears the maximum number of branches and fruits in soil with rich organic contents. However, it grows and bears fruits even under the condition of low organic contents. In YWPA, L. wilfordii is not distributed in high moor but widely distributed in low moor where tussocks by Carex thunbergii var. appendiculata are developed. It is mainly distributed on the top of tussocks also. Therefore, it is judged that the formation, growth, and extinction of tussocks by C. thunbergii var. appendiculata is closely related to the establishment, growth, and extinction of plants distributed in this space. It is assessed that the current YWPA has well-developed tussocks in which L. wilfordii is widely distributed, and extinction and re-establishment progress well. Accordingly, the L. wilfordii population is expected to be sustainable in the long term given if its current ecological process is maintained well.

• Korean Journal of Environment and Ecology
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• v.35 no.1
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• pp.48-67
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• 2021

Plant species exhibit current characteristics as a result of interactions with environmental conditions. The plants of Viola sp. have selected chasmogamous flowers with vigorous vegetative propagation or development of cleistogamous flowers as an adaptation strategy. Viola websteri is distributed on the Korean peninsula and the eastern part of Jilin Province, China. The center and edge of the distribution are expected to exhibit different population-dynamics. It is necessary to investigate the cause of its current limited distribution even though V. websteri has a mixed-mating strategy. Firstly, We examined the vegetation environment of habitats and evaluated its characteristics. Growth characteristics were examined through plant phenology. We then evaluated the population structure, characteristics of chasmogamous flowers, and productivity of cleistogamous flowers. Moreover, we compared population sizes between 2014 and 2018. Most habitats were located in deciduous broadleaf mixed forests adjacent to valleys. V. websteri produced chasmogamous flowers with self-incompatibility in April-May and cleistogamous flowers in June-September. The cleistogamous flower production is a strategy ensuring seed production under uncertain environmental fluctuations; these were approximately twice as numerous as chasmogamous flowers. The population structure was distinguished into stable and very unstable regions. There were sites where the population experienced a sharp decline in the 2018 compared to that of 2014. This large decline was found in the edge populations. The habitats had different microsites depending on the natural disturbances of drought and the matrix constituting the habitat, thus supporting various plants. Ensuring the production of seeds through cleistogamous flowers, it was determined that rapid seedling re-establishment and population replenishment were possible when the natural disturbance factor was removed. Environmental factors did not equally affect all populations or individuals. Therefore, it was expected that it would be able to persisted in a long time, despite the rapid decrease in the number of individuals in the population regionally. Local extinction and re-establishment are likely to repeat according to environmental change. We propose the additional population investigation based on this works are required. We also suggest a need to assess the long-term population dynamics and the genetic characteristics of chasmogamous flowers and cleistogamous flowers to establish and implement effective conservation strategies.

• KDI Journal of Economic Policy
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• v.12 no.3
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• pp.3-26
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• 1990

Encouraged by the investment in the rice paddy, the introduction of new varieties (Tong-Il), and the price support program, there has been great success in increasing rice production. Meanwhile, the demand for rice has decreased rapidly as per capita income continues to rise. Rice self-sufficiency has been attained, and a new over-supply problem is emerging. Moreover, the Uruguay Round Agricultural Negotiation would prohibit government price support for agricultural products. In October the Korean government decides the government purchase amount and support price, which works as the price guideline. All interested parties exert political efforts to influence the decision. The continued increase of the government purchase price of rice due to political pressure pushed the government purchase price above the market wholesale price in 1988. Also, the farmers preferred to sell to the government than to the wholesaler. This has discouraged the market mechanism, and the government is to take over the three functions of the market mechanism: stockpiling, seasonal price fluctuation adjustment, and circulation. Another big increase may cause the government purchase price to rise above the consumer price, which might lead to arbitrage opportunities for the farmers and suffocate the market mechanism. However, the current political situations limits the options for the Korean government. This paper argues that a supply control policy will reduce the social cost resulting from the high level of producer price support, and it proposes several second best policies: First, the production of new varieties should be reduced rapidly. Second, the old rice in the government warehouse should be auctioned or disposed of in order to reduce the government handling and management costs. Third, the acreage diversion program should be launched in order to control rice paddy acreage. Fourth, a social welfare program in rural areas should be introduced, since the share of population over 60 is increasing rapidly. Fifth, instead of the price support which is forbidden by the Uruguay Round, Korea should restructure the agricultural industry by developing new crops, by enhancing productivity and by improving the agricultural infrastructure.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.158-163
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• 1997

From July 1994 to August 1995, 32 patients underwent coronary artery bypass surgery. There were 14 men and 18 women. The mean age was 59 years (range from 37 to 81 years). Preoperatively 26 patients had unstable angina pectoris and 6 patients had stable angina pectoris. Nine patients had previous myocardial infarction hi tory. Five patients had preoperative left ventricular ejection fraction of 40% or less, The involved risk factors were as follows ; smoking 19 cases, hypertension 16 cases, hypercholesterolemia 14 cases, diabetes mellitus 6 cases, and obesity 3 cases.21 patients had three-vessel disease, 7 patients had two-vessel disease, 2 patients had one-vessel disease and 2 patients had left main coronary artery disease. We performed 103 distal bypasses out of 32 cases, and the mean number of grafts per patients is 3.22. We used arterial grafts (left internal mammary artery,)1, radial artery; 2) in 32% of total grafts. Postoperative complications were low cardiac output, perioperative myocardial infarction, respiratory failure and atrial fibrillation, etc. Early mortality was 6.25% (2/32). The causes of deaths were low cardiac output (1), and perioperative myocardial infarction(1).

• Journal of the Korean Regional Science Association
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• v.33 no.1
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• pp.69-85
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• 2017

The positive changes in urban space and urban activities resulting from the urban services provided by Smart City is not accomplished by simply creating the physical environment built on ICT but through the cooperation and participation of citizens and private sector, which is in fact key to success. In this study, this research analyzed the role and structure of smart governance, which is a system of horizontal cooperation between public and private sector, and analyze its role in developing Smart City. The study also proposes various ways to facilitate such development in each of critical categories. For this purpose, this research studied 228 smart services across 11 categories registered in the Ministry of Land and Transport in Korea to analyze the spatial distribution of smart services by spatial hierarchy and their characteristics Also, the research conducted a case study of MetroGIS, which is an information collaboration governance system for the greater area of Minneapolis and St. Paul in the state of Minnesota, United States, to explore how governance is formed; its organizational structure; the role of sub-level organization hierarchy and their interrelationship. The results of the analysis suggest that the following conditions are required to create a smart city: first, public sector resource assistance for building community; second, enhanced communication system within the community and with outside the community; securing financial stability and establishing a model of sustainable development to induce the community to evolve into a governance form.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.426-433
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• 2021

Investment in public sector information services has been on the rise in recent years. The supply of high-speed Internet and smartphones has become more common, and the stability of the information system provided to the public in the public sector has become an important management factor. In other words, tasks such as handling civil complaints and issuing certificates by public institutions, financial transactions by banks, customs clearance work, and e-commerce by individuals or institutions are mostly done online. Therefore, how to deal with obstacles arising from the information system, which is in charge of important civil service affairs, is becoming a very important issue. In other words, in the case of a disability that does not function normally even for a short period of time, various problems can occur when the work is delayed, as well as causing serious financial damage to the civil petitioner. This could be accompanied by a decline in public confidence and various other damages such as filing civil complaints. The reasons for the occurrence of information system failures are very diverse and realistically difficult to predict when. Among the various measures to cope with disability, this paper proposed a plan to establish a disability situation notification system that can minimize confusion caused by disability in the event of a homepage malfunction. The proposed disability situation notification system was established in the public IDC environment to show the possibility of utilization.

• The Journal of Engineering Geology
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• v.33 no.4
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• pp.555-571
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• 2023

Due to South Korea's concentrated summer rainfall, constituting 70% of the annual total, landslides frequently occur during the rainy season, necessitating accurate prediction methods to mitigate associated damage. In this study, a reduced-scale and full-scale slope was configured using weathered granite soil to find the possibility of establishing measurement management criterias through landslide reproduction. The experiment focused on matric suction, analyzing changes in ground properties and failure patterns caused by rainfall infiltration. Subsequently, an unsaturated infinite slope stability analysis was conducted. By calculating the failure time when the safety factor falls below 1 for each experiment, landslide prediction was demonstrated to be possible, approximately 17 minutes prior for the reduction-scale experiment and 6.5 hours for the full-scale experiment. These findings provide useful data for establishing Korean soil slope measurement management criteria that consider the characteristics of weathered granite soil.

• Korean Journal of Environment and Ecology
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• v.33 no.3
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• pp.303-320
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• 2019

Plants interact with various biotic and abiotic environmental factors. It requires much information to understand the traits of a plant species. A shortage of information would restrict the assessment, especially in the evaluation of what kind of factors influence a plant species to face extinction. Polygonatum stenophyllum Maxim. is one of the northern plants of which Korea is the southern distribution edge. The Korean Ministry of Environment had designated it to be the endangered species until December 2015. Although it is comparatively widespread, and a large population has recently been reported, it is assessed to be vulnerable due to the low population genetic diversity. This study evaluated the current distribution of Polygonatum stenophyllum Maxim. We investigated the vegetational environment, population structures, phenology, soil environment, and self-incompatibility based on the results. Lastly, we evaluated the current threats observed in the habitats. The habitats tended to be located in the areas where the masses at the edge of the stream accumulated except for those that were located on slopes of some mountainous areas. Most of them showed a stable population structure and had re-established or recruited seedlings. Polygonatum stenophyllum Maxim. had the difference in time when the shoots appeared above the ground depending on the depth of the rhizome located in the underground. In particular, the seedlings and juveniles had their rhizome located shallow in the soil. Visits by pollinator insects and success in pollination were crucial factors for bearing of fruits by Polygonatum stenophyllum Maxim. The threats observed in the habitat of Polygonatum stenophyllum Maxim. included the expansion of cultivated land, construction of new buildings, and construction of river banks and roads. Despite such observed risk factors, it is not likely that there would be rapid population reduction or extinction because of its widespread distribution with the total population of more than 2.7 million individuals and the new populations established by the re-colonization.

• (The)Study of the Eastern Classic
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• no.73
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• pp.153-184
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• 2018

The aim of this thesis was to examine the circumstances that led up to successful coin use across the entire nation in 1678 (the $4^{th}$ year of King Sukjong's reign), during the Joseon Dynasty. To this end, this thesis analysed the Sa-Mouk(事目, Provisions) that contained the institutional protocol for coin circulation, implemented by King Hyojong and the statesman Kim Youk(金堉) who had practical experience in these matters over the ten years of King Hyojong's reign(1649-1659). To regulate the problematic wide circulation of coarse cotton cloth as currency in the market of 1650 (the $1^{st}$ year of King Hyojong's reign), prohibition measures were implemented. Besides the superficial justification given for these measures(i.e., that the market price was disturbed by the use of coarse cotton cloth), there was another purpose to prohibiting the circulation of cotton cloth as money, following the standard ruled by the government: the state aimed to ensure momentum for the upcoming coin circulation policy, by strengthening its control of the current economy. In 1651 (the $2^{nd}$ year of King Hyojong's reign), the government fully cracked down on the use of coarse cotton cloth as currency, and simultaneously implemented its coin circulation policy in the Pyeongan(平安) region. The pretext for this policy was to raise finances to support people who were starving as a result of poor harvests and famine. People who received coins from government officials could purchase food in the market, and the coin circulation policy was judged to be successful. Subsequently, to extend coin circulation further throughout the region, the Sa-Mouk for Seoul was established. The Sa-Mouk included stipulations regarding the use of coin in transactions and for government expenditure; it aimed thereby to enhance the national policy's market credit. The hasty implementation of the policy for the expansion of coin circulation caused some problems that required its modification. In 1652 (the $3^{rd}$ year of King Hyojong's reign), coin circulation was increased to encompass the Gyeonggi(京畿) region, and some of the tax that had been paid in rice was now paid in coin. However, coins were in short supply, since there was insufficient copper, the main material used in coin production, and the policy faced a significant limitation. Therefore, in 1655(the $6^{th}$ year of King Hyojong's reign), a new Sa-Mouk for coin circulation was established. This Sa-Mouk included specifications regarding the determination of coin values based on rice and silver, and mandated the wide spread installation of stores for exchanging spot goods for coins throughout the region in which coins were circulating. This policy's objective was to secure stability for the national economy by further regulating coin circulation. The sustained implementation of the coin circulation policy for ten years by King Hyojong and the statesman Kim Youk offered the government an opportunity to accumulate experience in coin circulation in the market, and also to learn from institutional trial and error. This may have been one of the contributing factors to the nation-wide coin circulation that was established in 1678. The objective of the policy implemented during King Hyojong's reign was not to meet the market's requirements, but rather to ensure the preservation of the national economy, and this misjudgement constituted the policy's key limitation. At this time, the government urgently needed to secure finances to cope with the war against China's Qing Dynasty.

• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.382-387
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• 2014

The PC/ABS blends were manufactured with high shear rate processing. Changes of the blend morphology were analyzed according to the screw speed and processing time. To find optimal conditions of the high shear rate processing of the PC/ABS blend, blend morphology and size of the dispersed phase, ABS, were observed with a SEM. Also, tensile properties of the PC/ABS blends were measured to investigate the effect of the high shear rate process with the screw speed of 500 rpm to 3000 rpm for processing times of 10s to 40s. Especially, to observe the dispersed phase of the PC/ABS blend clearly, fracture surfaces of the PC/ABS blend were etched with chromic acid solution. As screw speed and processing time increase, dispersed phase size of the PC/ABS blend decreases and mechanical properties of the blend decrease as well. Especially, at screw speed over than 1000 rpm of high shear rate processing, mechanical properties of the PC/ABS blends decrease drastically due to the degradation of the blend during the high shear rate processing. Consequently, the optimal condition of screw speed of the high shear processing of the PC/ABS blend is set at 1000rpm, in this study. Under optimal condition, the PC/ABS blend has relatively high mechanical properties with the relatively stable micro-structure having nanometer scale dispersed phase.