• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권2호
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• pp.115-121
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• 2022

The Yezo sika deer (Cervus nippon yesoensis) is a subspecies of sika deer originated from Hokkaido, Japan. This paper is a study on the ecological impact caused by large mammals invading the ecosystem. Two pairs of deer were donated to the Agency for Defense Development in Taean in the late 1980s, and the population expanded to over 280 in 2018. The thermal imaging camera showed that the population ranged from 8 to 53 herds, divided into approximately 10 groups. It was confirmed that some of the herds had escaped the management area and invaded the nearby natural ecosystem, causing damage to cultivated land and natural vegetation. Herds of over 50 individuals have been studied in large grassland areas near drinking water sources such as streams and ponds. In places with excessive deer concentration, 1) feeding damage to herbs, shrubs and sub-trees, 2) tree withering due to antler-rubbing, and their habit of migrating along forest edges 3) excessive soil loss on slopes, 4) destruction of herbaceous layers due to compaction, and finally 5) damage to infrastructure were also investigated. As such, it is expected that the results of this study on the ecological and economic damage of Yezo sika deer can be used to predict the impact of other exotic sika deer in South Korea with similar behavioral characteristics and to establish a management plan.

• 한국태양광발전학회지
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• 제6권1호
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• pp.76-85
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• 2020

The Republic of Kazakhstan is a geographically large but sparsely populated country, rich in natural resources, located in the center of the Eurasian continent. In recent years, it has begun to create a green economy, leading it among its neighbors in Central Asia. Therefore, the country has set a clear goal: by 2030, emissions should be reduced by 15-25% compared to the level of the 90s. As part of the country green economy strategy, in 2013 Kazakhstan adopted the "National Concept for the Transition to the Green Economy until 2050", which sets out the principles of the green economy as a path for future development. The goal is to bring the share of renewable energy in electricity production from zero to 3% by 2020, and then increase it to 30% by 2030 and 50% by 2050. This paper looks at what Kazakhstan has done to promote renewable energy and provider perspectives. The paper also considers Kazakhstani legislation in terms of the development of renewable energy sources and provides information on incentives and preferences for the development of renewable energy sources. Thus, it will be easier for investors to evaluate the implementation of potential projects in Kazakhstan.

• 한국멀티미디어학회논문지
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• 제22권8호
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• pp.960-973
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• 2019

The increased use of smartphones has made it easier to plan travel. Especially for people travelling in Europe, it is common to move between cities by train, and reserving passes with a mobile app offers many advantages. The Czech Republic, which is a familiar destination for Koreans, is called the "heart of Europe" and it is in central Europe, so it is inevitable to use the railway when travelling. This study has been compared with the structural characteristics of the railway reservation service operated by the Czech and Korean railways. In general, when evaluating the usability of an app, we often use a method that allows a group of users or experts to spot problems. However, this study suggests an analytical method to obtain more reliable and objective results. Also, the analysis of the structural characteristics has an advantage that the problem can be predicted at the prototype stage. This, of course, comes with time and financial benefits. The purpose of this research is to contribute to the development of applications that are more convenient to use and efficiency of development.

• Strategy21
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• 통권43호
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• pp.201-224
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• 2018

The purpose of this study is to analyze the causes of a series of naval ship collisions in the United States 7 Fleet and diagnose the problems of the Republic of Korea Navy(ROKN). The ROKN should thoroughly analyze the lessons of the U.S. Navy's collisions and try to avoid the same cases in the future. In chapter 2, this article briefly explains how the USS Fitzgerald(DDG62) and USS John S. McCain(DDG56) have a collision with the civilian vessels. This paper uses three official documents published by the U.S. Navy in 2017 to get details of incidents. In chapter 3, this paper analyzes the cause of the two incidents. According to the official reports, two aegis ships have complex problems. First, executives significantly lacked the seamanship and qualification. Second, there were no organizational culture and teamwork to form the right decisions. Also, there was a structural problem inside the 7 Fleet itself. In chapter 4 and 5, this study applies some lessons to the ROKN. Especially, this chapter suggests policy recommendations to prevent the similar incidents from occurring in the ROKN. The ROKN should be aware of the possibility that the sorts of incident could occur any time.

• 한국환경과학회지
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• 제32권11호
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• pp.789-800
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• 2023

A vascular flora survey was conducted in 2020 to identify flora and analyze changes in the numbers of vascular flora species over the past 10 years at Gongju-weir (GW) and Baekje-weir (BW) in the Geumgang River, Republic of Korea. A total of 241 taxa were found in GW and 279 taxa in BW, and 208 taxa (88% of total taxa) were common species. The distribution of invasive species in GW and BW were seven and eight taxa, respectively. Rare plants were not identified in any of the weirs. The Poaceae family dominated in terms of number of species, followed by Asteraceae, Legumes, Cyperaceae, and Polygonaceae. Additionally, Therophytes accounted for a high proportion of Raunkiaer life forms. The numbers of vascular plant species, total taxa, naturalized plants, and invasive species have been increasing over the last 10 years. However, long-term alterations in invasive species before and after the opening of the weirs increased much more significantly in the partially opened BW than in the fully opened GW. These results indicate that the degree of barrier opening does not affect the invasion and establishment of non-native species.

• 대한간호학회지
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• 제49권2호
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• pp.161-170
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• 2019

Background: Quality ratings could provide vital information to help people in choosing a nursing home. Purpose: This study investigated factors aligned with quality ratings of nursing homes. Methods: We employed a cross-sectional descriptive design to assess publicly available data on 1,354 nursing homes with 30 or more beds in the Republic of Korea. After excluding 289 nursing homes with no reported quality-evaluation ratings, we analyzed the 2015 data of 1,065 nursing homes. To prevent multicollinearity among independent variables, we carefully selected the final set of variables based on clinical and theoretical meaningfulness to direct nursing care. Quality, the ordinal outcome, was scored from 1 to 5 with a higher score indicating higher quality of the organization. We constructed a multivariate ordered logistic regression model. Results: Higher quality ratings of nursing homes was significantly related to the number of unoccupied beds (OR=0.99, p=.024), registered nurses (RNs) (OR=1.30, p=.003), qualified care workers (OR=1.03, p=.011), cognitive-improvement programs (OR=1.05, p=.024), and other programs for residents' activities (OR=1.09, p<.001). Conclusion: The number of RNs had the strongest influence on the publicly reported quality rating, while the rating of qualified care workers demonstrated little effect and that of nursing assistants had no effect. The number of RNs could be used as a crucial indicator for high-quality homes; more resident-engaging programs also demonstrated better quality of nursing home care.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권4호
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• pp.403-411
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• 2012

This study presents the nano-sized particle emission characteristics from a small turbocharged common rail diesel engine applicable to prime and auxiliary machines on marine vessels. The experiments were conducted under dynamic engine operating conditions, such as steady-state, cold start, and transient conditions. The particle number and size distributions were analyzed with a high resolution PM analyzer. The diesel oxidation catalyst (DOC) had an insignificant effect on the reduction in particle number, but particle number emissions were drastically reduced by 3 to 4 orders of magnitude downstream of the diesel particulate filter (DPF) at various steady conditions. Under high speed and load conditions, the particle filtering efficiency was decreased by the partial combustion of trapped particles inside the DPF because of the high exhaust temperature caused by the increased particle number concentration. Retarded fuel injection timing and higher EGR rates led to increased particle number emissions. As the temperature inside the DPF increased from $25^{\circ}C$ to $300^{\circ}C$, the peak particle number level was reduced by 70% compared to cold start conditions. High levels of nucleation mode particle generation were found in the deceleration phases during the transient tests.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권1호
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• pp.9-19
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• 2012

A set of equations of motion is derived for vibratory motions of an underwater cable connected to a moving vehicle at one end and with drogues at the other end. From the static analysis, cable configurations are obtained for different vehicle speeds and towing pretensions are determined by fluid resistance of drogues. Also the dynamic analysis is required to predict its vibratory motion. Nonlinear fluid drag forces greatly influence the dynamic tension. In this study, a numerical analysis program was developed to find out the characteristic of cable behaviour. The motion is described in terms of space and time coordinates based on Chebyshev polynomial expansions. For the spatial integration the collocation method is employed and the Newmark method is applied for the time integration. Dynamic tensions, displacements, velocities, accelerations were predicted in the time domain while natural frequencies and transfer functions were obtained in the frequency domain.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권4호
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• pp.274-278
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• 2021

Road structures play an important role in collisions involving vehicles and wildlife. Our study aimed to determine the effect of various types of road structures on the risk associated with roadkill. We surveyed 50 previously identified roadkill hotspots, ranked from one to five according to roadkill density. We collected nine types of road structure data on each hotspot road section. Structures with similar characteristics were grouped together, resulting in five categories, namely, median barrier, high edge barrier, low edge barrier, speed, and visibility. We examined the existence of each road structure category at each hotspot rank. The cumulative link model showed that the absence of bottom blocked median barrier increased the roadkill hotspot rank. Our study concluded that a visual obstacle in the middle of roads by the median barrier decreases wildlife road crossing attempts and roadkill risk. We suggest that future roadkill mitigation plans should be established considering these characteristics.

• Parasites, Hosts and Diseases
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• 제45권3호
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• pp.199-204
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• 2007

Metacercariae of Gynaecotyla squatarolae (Digenea: Microphallidae) were discovered from the shore crab, Macrophthalmus dilatatus, purchased at a market in a coastal town of Taean-Eup, Chungcheongnam-do, Republic of Korea. Their adult flukes were confirmed by experimental infection of rats. The metacercariae of G. squatarolae were elliptical ($391.1{\times}362.5{\mu}m$), and the excysted metacercariae had progenetic genital organs, including the ovary and testes. To obtain adult flukes, 6 Sprague-Dawley rats were fed 500 metacercariae each, and killed at days 2, 4, and 6 post-infection. The adult flukes were identified as G. squatarolae (Yamaguti, 1934) Yamaguti, 1939, based on morphological characters, including 2 ventral suckers (1 large and 1 small), a large genital atrium equipped with the cirrus and the metraterm, separated male and female genital pores, a transversely long cirrus pouch, and extensive vitelline follicles. In the present study, it has been first proven that the shore crab M. dilatatus is a second intermediate host for G. squatarolae in the Republic of Korea.