• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.3
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• pp.209-222
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• 2024

The Earth Pressure Balance (EPB) shield Tunnel Boring Machine (TBM) is widely used for underground tunnel construction for its advantages, such as eliminating the need for additional facilities compared to the slurry shield TBM, which requires Slurry Treatment Plant (STP). During EPB shield TBM excavation, a soil conditioning technique is employed to enhance the physical properties of the excavated soil by injecting additives, thus broadening the range of applicable ground conditions to EPB shield TBMs. This study explored the use of xanthan gum, a type of biopolymer, as an alternative to the commonly used polymer additive. Biopolymers, derived from biological sources, are fully biodegradable. In contrast to traditional polymers such as polyacrylic acid, which contain environmentally harmful components, xanthan gum is gaining attention as an eco-friendly material due to its minimal toxicity and environmental impact. Test conditions with similar workability were established through slump tests, and the rheological characteristics were assessed using a laboratory pressurized vane shear test apparatus. The experiments demonstrated that, despite exhibiting similar workability, the peak strength in the flow curve decreased with increasing the content of xanthan gum. Consequently, a correlation between the xanthan gum content and peak strength was established. Replacing the traditional polymers with xanthan gum could enable stable EPB shield TBM operation by reducing equipment load, in addition to offering environmental benefits.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.96-102
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• 1985

A study on the competition-ecological classification of the 10 prominent paddy weed species around bulrush (Scirpus juneoides) to simplify the weed problem concept for the rice production. A serial assessments on the competition ability in space and dry matter production(nutrient depletion) of respective weed species and paddy rice, and the data were used to compute the phenotypic similarity by Single Link Clustering method. Both growth response of weed species in mono- and under the paddy rice standing was very similar (r = 0.969), but the reduction rate as affected by paddy rice standing was negatively correlated with the ability in space-competition(r=-0.513). Dendrogram of 10 weed species based on the phenotypic similarity computed in 4 characters in mono- and under the paddy rice standing was also similar, as Echinochloa c., Ludwigia p., Cyperus s., and Scirpus m. in I-group, Eleocharis k., Scirpus j, in II-group, and Juncus e., Potamogeton d. in III-group, respectively. Also, that of paddy rice to 10 weed species showed Fimbristylis m., Scirpus j., Eleocharis k., Scirpus m., Juncus e. in I-group, and Ludwigia p., Potamogeton d., Monochoria v. in II-group, respectively. The integrated dendrogram by the above two data indicate the I-group with Fimbristylis m., Scirpus j., Eleocharis k. and Juncus e., as higher growth response with relatively lower competition ability to paddy rice, II-group with Cyperus s., Echinochloa c., Potamogeton d., and Ludwigia p., as higher both in growth and competition, and the last, III-group with Monochoria v., and Scirpus m., as lower growth but higher competition, respectively.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.26-26
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• 2019

본 연구는 2016년부터 2017년까지 한국 정부가 선정한 다수의 도시재생사업 중 수변공간 관련 사업을 선별하여 세부내용을 살펴보고 수변공간 도시재생사업의 거버넌스 특성을 분석한다. 도시재생사업에서 거버넌스는 사업의 성패를 가르는 핵심 요소로 대두되고 있다. 특히, 협업을 통한 민간 커뮤니티의 역할과 주민참여는 더욱 중요한 비중을 갖게 되었다. 본 연구는 Tallon(2013)의 도시재생 거버넌스 네 가지 형태-관주도(top-down), 주민주도(bottom-up), 시장주도(market-led), 지주주도(property-led) 재생을 기준으로 도시재생사업 활성화계획의 세부내용을 분석한다. 향후 도시재생사업의 추진 및 시행단계에서 거버넌스의 역할이 제대로 작동할 수 있도록 시사점을 제공하고자 한다. 연구의 공간적 범위를 수변공간을 한정하여 분석한 결과 총 20개의 도시재생사업이 도심 내 하천변과 해안가를 활용하여 추진되고 있었다. 구체적인 사업의 형태로는 (1) 생태하천복원, (2) 역사문화자원을 연계한 수변관광지 개발, (3) 수변네트워크 녹지 산책로 조성 (4) 항구 기반 수변도시개발 및 도심재생, (5) 섬의 이점을 활용한 수변경관사업, (6) 조선업 침체지역재생 등이 있었다. 한국의 수변공간 도시재생사업은 가장 일반적인 도시재생방식인 '관주도'로 진행되고 있었다. 그러나 지역의 권한과 역할을 강화하고자 하는 노력은 우선시되고 있었다. 또한, 관계부처 및 공공기관과의 파트너십 구축을 통한 도시재생사업의 효과성 향상을 도모하고 있었다. 특히, 부산시 영도구와 경상남도 통영시의 도시재생사업에서 협업의 노력이 두드러지게 나타났다. '마을만들기'와 같은 주민주도의 도시재생방식은 '주민참여협의체'를 통하여 일부 반영되고 있었다. 예를 들어, 서울시 도봉 노원구, 인천시 부평구, 경상남도 김해시, 부산시 영도구 등이 해당한다. 그러나 구체적인 실천 방안을 통한 주민주도 도시재생 거버넌스를 구축하는데는 부족함을 보였다. 더불어 민간투자를 유치하는 시장주도의 도시재생 접근은 찾아볼 수 없었다. 도시재생사업의 장기적이고 통합적인 특성을 고려했을 때, 안정적인 도시재생사업 추진을 위한 재원 마련에 대한 지속적인 노력이 요구된다.

• Clean Technology
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• v.30 no.1
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• pp.62-67
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• 2024

In this study, an alkali metal Na was introduced into iron-based catalysts used in the carbon dioxide-based Fischer-Tropsch process by wet impregnation and physical mixing methods to compare their performance. The as-prepared catalysts were evaluated for reactivity at 3.5 MPa, 330 ℃, feed ratio of H₂/CO₂ = 3 with a space velocity of 4,000 mL h^-1 g_cat^-1. Comparing the two catalysts, it was found that Na was uniformly distributed throughout the catalyst when wet-impregnated, but Na for physically mixed catalyst was relatively located on the surface of the catalyst. In addition, the wet-impregnated catalyst showed higher liquid hydrocarbon (C₅₊) yield and lower CO selectivity. In conclusion, the effect of Na distribution in the catalyst on the reaction was identified and can be controlled by the introduction method.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.4
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• pp.203-215
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• 2006

Field observations on the spatio-temporal distribution of organic matter of the surface sediment were carried out at 15 stations in the central parts of the South Sea of Korea from April 2002 to January 2003. The range of water temperature and salinity in bottom waters, mud content and water content of surface sediment were $8.06{\sim}23.35^{\circ}C,\;29.20{\sim}34.51\;psu,\;71.2{\sim}99.9%$ and $38.7{\sim}68.9%$, respectively. Measured parameters on the surface sediments of ignition loss (IL), chemical oxygen demand (CODs), phaeopigment, particulate organic carbon (POC) and particulate organic nitrogen (PON) also ranged in $3.9{\sim}l2.5%,\;9.60{\sim}44.05\;mgO_2/g-dry,\;1.58{\sim}29.51\;{\mu}g/g-dry,\;3.12{\sim}13.01\;mgC/g-dry$ and $0.49{\sim}2.00\;mgN/g-dry$, respectively. The spatio-temporal distribution of organic matter demonstrated higher concentrations offshore than at lesions near the coastal line. Higher concentrations occurred in the summer and spring. The results indicated that the origin of organic matter in surface sediments in the central part of the South Sea was autochthonous rather than allocthonous because the organic matter had an average C/N ratio of 6.44 (${\pm}0.51$). However, the composition of autochthonous organic matter was mainly derived from detritus rather than living phytoplankton, which was Indicated by the results of the POC/phaeopigment ratio. A principal component analysis (PCA) indicated that 73.2% of the variability in the data was described by two factors: 1) an 'environmental factor concerning the accumulation of materials (57.3%)' and 2) 'origin of organic matter and the composition by primary production (15.9%)'. The sedimentary environment in the central part of the South Sea was divided into four regions from the factor score of the PCA by the concentrations of organic matter and the composition ratio of organic matters from phytoplankton in surface sediments.

• 지역과문화
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• v.6 no.4
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• pp.23-45
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• 2019

The main research is on how to find source stories and develop and utilize content that will properly show the value of Panmunjom and the surrounding DMZ on the Korean Peninsula, which are receiving worldwide attention. Three methods were used as research for the high-end branding of Panmunjom and the surrounding DMZ. The first is the interest of prospective visitors through the travel cycle, using Joseph Campbell's "The Hero's Journey." The second was to incorporate Roland Bart's "third meaning" into the subjective travel and emotional stimulation, which is the trend of modern travel. The third introduced Kevin Lynch's theory and tried to place five elements of the path, edge, district, node and landmark in the core location of Panmunjom. Through the study, the excavation of contents in Panmunjom and the surrounding DMZ needs to be collected to a third meaning using a direct interview method that listens to the stories of related figures as well as organizing historical events. The priority should be given to those over the age of 80 and interviews should be conducted at least three times and over three generations. The process of building it into an archive, selecting a story, and then going through a culture collage and networking and branding takes place in five stages. This can create a virtuous circle of content processing, content utilization, job creation in the region and revitalizing the local economy through discovery of source stories and storytelling. Content development should be able to touch sensibility while saving time, history, place, originality and sincerity. Taking the center between tourism and travel, development and damage concerns, a careful but long-term plan and large-scale discovery of source stories should be made, and a consensus should be formed on the need for proper storytelling.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.17-26
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• 2023

The integrated underground space map is a three-dimensional map that integrates 16 types, including 7 types of underground facilities, 6 types of underground structures, and 3 types of ground. In order to systematically construct, manage, and utilize the integrated underground space map, it was institutionalized as the "Special Act on Underground Safety Management," and the "Underground Space Integrated Map Production Work Regulations" was prepared as detailed work regulations. However, there is a lack of institutional mechanisms to develop new technologies such as the completed book submission system for submitting change information and automation technology for updating the integrated underground spatial map and to expand the usability of the integrated underground spatial map. Accordingly, this study examined the current status of the integrated underground space map and attempted to suggest a direction for improving the current system through a revision plan and detailed operation management regulations (draft) of the Special Act on Underground Safety Management.

• Proceedings of the Korea Society of Design Studies Conference
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• 2004.05a
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• pp.44-45
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• 2004

With the development of informational machinery and tools in the modern industrial society, the image is expressed diversely as tools of informational transmission and artistic communication. This image is revival equipment and transmissional media in which sound and light are comprehensively formed. The image's intuitive and sensational expressivity can revive subjects and express a fiction, a reality, a nonfiction, and a virtual reality as a communication tool that has synchronicity and the medium of meaning. Because of this, the domain of the image will be gradually extended in the future, and the world of cognizance that can be detected across our living space will absorb the image diversely and react. In this context, the investigator examined what influence image media and equipments have in space as spatial equipments, based on the recognition of cerrelation among the image, space, and mankind, namely, the environmental meaning the mage and the space contain. Therefore, this study was conducted from the aspects of relationship establishment between image equipments that are ever expansive to a variety of domains and the space that accommodates the equipments. As study findings, the influences the image equipments have on space and their expressional features are presented in three aspects: 'the expressional medium of mutual synergy','metaphysical ultra-epithelial space constituent',' and 'object'. This study seems to be meaningful in that we can expect the spatial approach method by purposes and spatial layout of image structures, with this study, through analyzing the meaning of relationship between image equipments and space.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.2
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• pp.232-237
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• 2018

According to the MAIIF report, from 1998 to 2009, 101 incidents involving entering enclosed spaces aboard ships resulted in 93 deaths and 96 casualties. IMO has therefore amended the Recommendations for entering Enclosed Spaces Entry and SOLAS 1974 Convention Chapter 3 Regulation 19, which mandates enclosed spaces entry and rescue drill on a regular basis. The training of entering such enclosed spaces should be practical, recognizing all possible risks of entering enclosed spaces aboard ships, while also considering the safety of trainees during the training. Recently, educational contents utilizing virtual reality (VR) have been applied in various fields to improve education and training effects, and these methods have proven to have advantages in actual and repetitive learning without being limited to physical space. In this study, the effectiveness, characteristics and differentiation of training of entering enclosed spaces aboard ships using VR were compared with traditional class room lectures through quantitative evaluation and questionnaires of training participants. Through the evaluation and questionnaire, it was found that participants using VR understood and learned the required training elements better than the control group, all of whom were trained through the normal class room lecture. Moreover, participants reported to display preference for training with the help of VR. As a result of the study, it was confirmed that the learning effects of VR onboard training can be used as an effective training method, especially by using video and other types of simulators.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.262-271
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• 2000

This study was carried out to clarify the spatial and temporal patterns of benthic environments and macrobenthos on the subtidal soft-bottom in Chonsu Bay. Seasonal surface water temperature was similar to the bottom layer, but freshwater discharges into the outlets dereased the surface salinity around the dyke in summer. Bottom dissolved oxygen was decreased deeply around the dyke and created the de-oxygenated layer during summer. Sediment grain size was consisted of finer at the neighboring of the dyke than the mouth of the bay. Organic matters including the sediment were decreased at the mouth of the bay. A total of 311 species ($769\;ind./m^2$) were identified. Polychaetes were the most abundant faunal group in the number of species and densities. The number of species revealed the spatial patterns that it was higher in the mouth of the bay, and their densities showed seasonal changes by mass recruitment occurred at the most of the area in summer, At this time, opportunistic species, Lumbrineris iongifolia and Theora fragilis, were also recruited massively. Chonsu Bay were classified into five station groups by the cluster analysis. The dominant species around the dyke were composed to opportunistic species, those in middle area were Sternaspis scutata, Paraplionospio pinnata, and those in the mouth of the bay were Mediomastus californiensis, Nephtys polybranchia. Seasonal fluctuations and spatial difference of environments seem to have influenced to the species compositions and affected to the stability of benthic ecosystems spatial-temporally In Chonsu nay.