• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.679-686
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• 2006

Recently, the city railway in the Seoul Metropolitan Area (SMA) has offered a low quality of service as a passage time, because it was operated slowly. So, the people who live in modern society are not satisfied about passage time, therefore, this study tried to make that the subway in the SMA becomes a more functional and effective wide-area-transportation-network through an express train introduction's method which examined cases from abroad and current system. and then presented how express train could be applied to current system. In a case study, We used the An-San Line and Su-In Line as a examples and developed a schedule which can minimize the delaying time of subway by using Branch & Bound Algorithm. The train operational plan was loaded to consider a railroad siding, Obtained site, and the dispatch interval(three to ten minutes) for the express and local lines and finally, We presented an alternative operational plan which made by those factors.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4D
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• pp.469-476
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• 2008

Recently, TOD gains popularity as a traffic solution measure of high density urban regeneration projects. The purpose of this study is to investigate traffic impacts of high density TOD projects, and to identify the issues to be resolved. For a case study, it chooses Gangnamgucheong station in Gangnam area served by two subway lines, and designates 400m radius from the station as a site for high-density development. The MOEs chosen for this study is traffic volume, time, distance, speed, and mode share. The SECOM model is adopted for traffic simulation. The analysis results show that high-density TOD is an effective tool for traffic improvement even with only one station area being implemented. It is found that the traffic volume increases near the station in nature where high-density development occurs, but it declines overall in the rest of Gangam area. The total travel time and distance of passenger vehicles decline, meaning that the traffic condition becomes better than before. With regulation on parking supply, the improvement becomes more vivid. In terms of the changes of traffic speed, both alternatives show 4.1% increase in speed, but the difference between alternatives is not quite noticeable because of the induced vehicle demand driven to the streets with improved traffic condition. The mode share changes occur for the benefit of subway ridership, because the study station is equipped with two subway line services. When mixed with parking supply restriction, the impact becomes clearer.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.41-51
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• 2023

As abnormal climatic event occur frequently due to global warming, many nations have proclaimed their commitment to achieving carbon neutrality and are actively pursuing a transition toward a hydrogen economy. At this time, ammonia has garnered significant attention not only as a high-capacity hydrogen carrier but also as a promising candidate as a carbon-free fuel. In particular, anion exchange membrane fuel cells offer the advantage of directly supplying ammonia to the fuel cell, eliminating the necessity for separate ammonia decomposition or hydrogen purification. Therefore, in this study, the operation principle and research trend of the anion exchange membrane fuel cell are reviewed, and several research using ammonia as a fuel in anion exchange membrane fuel cell are also investigated.

• Korean Journal of Ichthyology
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• v.36 no.2
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• pp.174-181
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• 2024

This study examines the community characteristics of fish species collected by fyke net from the eastern coastal waters of Yeosu, Korea, during the period from 2020 to 2021. A total of 4,539 fish were sampled and classified into 43 species, 28 families, and 7 orders. The dominant species included Mugil cephalus (14.4%), Konosirus punctatus (10.9%), Lateolabrax japonicus (8.3%), Acanthopagrus schlegelii (7.9%), and Pennahia argentata (7.2%). The diversity index was highest in October (H'=2.888) and lowest in February (H'=2.075). Furthermore, the dominance index was highest in March (DI=0.524) and lowest in December (DI=0.178). Hierarchical cluster analysis (HCA) revealed that fish communities could be divided into three groups based on Bray-Curtis similarity. Group 1, consisting mainly of species collected from June to October, formed one cluster. Group 2, including winter spawning species such as Pseudopleuronectes yokohamae, Clupea pallasii, and Hexagrammos otakii, sampled from November to February, formed another cluster. Group 3, which included species such as Larimichthys polyactis, Amblychaeturichthys hexanema, and Sebastes inermis, formed a cluster collected from March to May. The eastern coast of Yeosu is considered a suitable habitat for fisheries resources, including highly economically valuable species, and it is also assumed to be an important spawning and nursery ground for many fish species.

• Journal of Environmental Policy
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• v.5 no.1
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• pp.45-70
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• 2006

China has achieved great economic growth above 9% annual since it changed to more of a market economy system by its reform and open-door policy. At the same time, China has experienced severe ecological deterioration, such as air and water pollutions caused by its rapid urbanization and industrialization. China is now confronted with environmental pollution and ecological deterioration at a critical point, at which economic development in China is limited. Moreover, environmental problems in China have become a lit fuse for social fluctuation beyond pollution problems. The root and background of environmental problems in China, firstly, are its government's lack of understanding of these problems and incorrect economic policies affected by political and ideological prejudice. Secondly, the plundering of resources, 'the principle of development first' which didn't consider environmental sustainability is another source of environmental deterioration in China. In addition, a huge population and poverty in China have increased the difficulty in solving its environmental problems, and in fact have accelerated them. The Chinese government has established many environmental laws and institutions, increased environmental investments, and is enlarging the participation of NGOs and the general public in some limited scale to solve its environmental problems. However, it has not obtained effective results because of the lack of environmental investments owing to the government's limit of the development phase, a structural limit of law enforcement and local protectionism, and the limit of political independency in NGOs and the lack of public participation in China. It seems that China remains in the stage of 'economic development first, environmental protection second', contrary to its catch-phrase of 'the harmony between economic development and environmental protection'. China is now confronted with dual pressure both domestically and abroad because of deepening environmental problems. There are growing public's protests and demonstrations in China in response to the spread of damage owing to environmental pollution and ecological deterioration. On the other hand, international society, in particular neighboring countries, regard China as a principal cause of ecological disaster. In the face of this dual pressure, China is presently contemplating a 'recycling economy' that helps sustainable development through the structural reform of industries using too much energy and through more severe law enforcement than now. Therefore, it is desirable to promote regional cooperation more progressively and practically in the direction of building China's ability to solve environmental problems.

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.10-21
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• 2000

Purpose: Episodic memory is described as an 'autobiographical' memory responsible for storing a record of the events in our lives. We performed functional brain activation study using ${H_2}^{15}O$ PET to reveal the neural basis of the encoding and the retrieval of episodic memory in human normal volunteers. Materials and Methods: Four repeated ${H_2}^{15}O$ PET scans with two reference and two activation tasks were performed on 6 normal volunteers to activate brain areas engaged in encoding and retrieval with verbal materials. Images from the same subject were spatially registered and normalized using linear and nonlinear transformation. Using the means and variances for every condition which were adjusted with analysis of covariance, t-statistic analysis were performed voxel-wise. Results: Encoding of episodic memory activated the opercular and triangular parts of left inferior frontal gyrus, right prefrontal cortex, medial frontal area, cingulate gyrus, posterior middle and inferior temporal gyri, and cerebellum, and both primary visual and visual association areas. Retrieval of episodic memory activated the triangular part of left inferior frontal gyrus and inferior temporal gyrus, right prefrontal cortex and medial temporal area, and both cerebellum and primary visual and visual association areas. The activations in the opercular part of left inferior frontal gyrus and the right prefrontal cortex meant the essential role of these areas in the encoding and retrieval of episodic memory. Conclusion: We could localize the neural basis of the encoding and retrieval of episodic memory using ${H_2}^{15}O$ PET, which was partly consistent with the hypothesis of hemispheric encoding/retrieval asymmetry.

• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.37-49
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• 2008

In general, most of the firms do not settle down in one place for their pursuit of profit. There are many reasons for the relocation of the firms; procurement of raw material, market area, transportation cost and housing cost. The aspect of national policy, firm relocation has been systemically promoted for the purpose of logistics system efficiency. Nowadays balanced regional development has been issue. Another aspect, many countries have struggled for the preoccupancy of new place because of its production cost saving and curtailment of expenditure. The aim of this article is qualitative and quantitative analysis of relocation influence factors of domestic goods firms in Korea. This article dynamically analyzed the relocation influence factors for domestic goods firms in Korea. For the analysis this article made use of complementary survey (2006) out of the 3rd national logistics survey (2005). The complementary survey conducted pre-business district, business period, relocation reason, etc. This article dynamically analyzed from the three aspects; observation of average residence time in one business district, relocation factors, influence of market area. Analysis shows that relocation of firm is very high rate and the reasons of relocation play compositeness role. The results of determinants of location, firms approach the established market area closely and the firm's relocation is influenced by market area.

• Investigative Magnetic Resonance Imaging
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• v.8 no.1
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• pp.9-16
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• 2004

Purpose : The purpose of this study was to assess supplementary motor area (SMA) activation during motor, sensory, word generation, listening comprehension, and working memory tasks using functional magnetic resonance imaging (fMRI). Materials and Methods : Sixteen healthy right-handed subjects (9M, 7F) were imaged on a Siemens 1.5T scanner. Whole brain functional maps were acquired using BOLD EPI sequences in the axial plane. Each paradigm consisted of five epochs of activation vs. the control condition. The activation tasks consisted of left finger complex movement, hot sensory stimulation of the left hand, word generation, listening comprehension, and working memory. The reference function was a boxcar waveform. Activation maps were thresholded at an uncorrected p=0.0001. The thresholded activation maps were placed into MNI space and the anatomic localization of activation within the SMA was compared across tasks. Results : SMA activation was observed in 16 volunteers for the motor task, 11 for the sensory task, 15 for the word generation task, 5 for the listening comprehension task, and 15 for the working memory task. The rostral aspects of the SMA showed activity during the word generation and working memory tasks, and the caudal aspects of the SMA showed activity during the motor and sensory tasks. Right (contralateral) SMA activation was observed during the motor and sensory tasks, and left SMA activation during the word generation and memory tasks. Conclusion : Our results suggest that SMA is involved in a variety of functional tasks including motor, sensory, word generation, and working memory. The results obtained also support the notion that functionally specific subregions exist within the region classically defined as the SMA.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.12
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• pp.1390-1399
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• 2007

Samples of 45 school dust were collected in Daegu in January 2007, were sieved below 100 ${\mu}m$, and 14 elements were analyzed using ICP after an acid extraction. Results obtained from the source assessment of trace elements using enrichment factor showed that dust from playground were influenced by natural sources, while dust from classroom were influenced by urban anthropogenic sources. The measured values were remarkably higher in components from natural sources than in components from urban anthropogenic sources. Dust from classroom are highly concentrated than those from playground. Concentrations of dust in urban area are similar to those of dust in rural area and there was no significant difference in concentrations between classroom with playground soil and classroom with play-ground grass. Compared with other cities in Korea, concentrations of heavy metals in Daegu city were higher in classroom and lower in playground than those of heavy metals in other cities. Dust from classroom contained lower concentrations of trace elements than those from street in Daegu. Results of pollution indices of heavy metals indicated that playground was not contaminated with heavy metals and classroom was considered to be highly contaminated. No appreciable differences in playground were found between urban and rural areas but in case of classroom pollution, heavy metal concentrations were a little bit higher in urban areas than in rural areas. The correlation analysis among trace elements indicated that components in playground were significantly correlated, while components in classroom were less correlated. Trace element components of classroom dust were not significantly affected by those of playground dust.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.3
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• pp.67-75
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• 2017

The culture of Gugok (九曲) and Dongcheon (洞天), which tries to reach the ideological culmination in Confucianism, was widespread throughout the Joseon dynasty. This was an extension of the spirit of studying and honoring Zhu Xi (學朱子, 尊朱子); thereby, Confucian scholars in Joseon expressed the will to follow the teachings of Zhu Xi (朱子) and comforted themselves that they were in the course of attaining the truth. As a realization of this expression of will, scholars designated and operated various scenic sites as Gugoks, following the example of Zhu Xi's Mui Gugok (武夷九曲), and Dongcheons, as a representation of the utopia. These designations are widespread nationwide, with around sixty Gugok locations that have now been reported in academia. However, the actual number of Gugoks exceeds this number, and many of them are currently not identified concerning the exact locations. Therefore, the purpose of this study is to identify the locations of Gugoks and Dongcheons scattered around Seoul, Gyeonggi and Gangwon regions. For the coordinates of Gugoks and Dongcheons, this study referred to the literature, web search and the books published by local cultural institutes. Based on the collected information, the researchers conducted field trips to investigate whether the record exists as a real location and, if so, acquired their coordinates. This study also provides the tables of Gugok or Dongcheon that only exists in the imagination, existed before but now are lost, or are inaccessible. Eight locations in Seoul, Gyeonggi, and Gangwon regions are understood as Gugok. Among them, Gogun Gugok and Okgye Gugok have relatively clear locations and records. Byeokgye Gugok and Suhoe Gugok, on the other hand, has many locations and titles overlapped, and their established time and managers are unclear. As for Ui Gugok in Seoul, it is known to be set by Hong Yangho, but some parts of its locations are confirmed, others are in dispute, and many locations are damaged. Thirty-eight locations in Seoul, Gyeonggi, and Gangwon regions are understood as Dongcheon. There are sixteen Dongcheons in Seoul area. Among them, those including Dohwa Dongcheon, Yangsan Dongcheon, and Ssangnyu Dongcheon actually exist but are forbidden to be accessed. There are thirteen Dongcheons in Gyeonggi area. The exact location of Onsu Dongcheon cannot be confirmed because of the development; Gwirae Dongcheon has historical records, but the actual existence cannot be confirmed. There are nine Dongcheons in Gangwon area. The researcher judged that Hwaeum Dongcheon is the misspelled record of Hwaeumdong Jeongsaji (華陰洞精舍址), which is located at the upstream of Gogun Gugok.