• Journal of Advanced Marine Engineering and Technology
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• 제41권1호
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• pp.8-14
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• 2017

2008년 금융위기로 인하여 세계 경제가 어려워지면서 국제 유가 상승과 물동량이 감소하였으며, 대다수의 대형선사들은 차선책으로 대형선박 발주, 항로변경 및 운항방식 등을 개선하여 적자폭을 줄이게 되었다. 특히, 저속 운항 방식은 눈에 띄는 연료비 절감으로 많은 선주사들로부터 호응을 얻었으나 장기간 저속 운전시 고속 운전에 최적화된 주기관의 재킷 청수 냉각시스템은 정상 운전온도를 유지하지 못하고 하강하여 저온부식의 발생을 가속화 하게 되었다. 이로 인해 엔진의 부하가 낮을 경우 기존에 설치되는 재킷 냉각수 냉각기의 역할은 감소하고 조수기의 사용도 제한이 됨으로 재킷 청수 냉각 시스템의 개선이 필요하게 되었다. 본 논문에서는 선박의 저속운항에 따른 선박용 디젤 주기관의 냉각시스템 개선 사항을 검토하기 위하여, 파나막스급 산적화물선인 82k와 케이프급 산적화물선 180k 선박들을 대상으로 주기관 재킷 냉각수 냉각기를 설치 및 미설치하여 주기관 청수 냉각 시스템의 성능 결과를 검토 및 비교 분석 하여, 현 저속 운항선박에 탑재되는 주기관의 성능변화에 적절한 냉각시스템의 설계 개선방안을 제안하였다.

• 상하수도학회지
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• 제30권5호
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• pp.521-532
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• 2016

Seawater desalination market after global economic crisis has been stalled due to the market uncertainties and decreased demand in desalination. It is important to review the status of the market and to estimate the appropriate share of Forward osmosis-Reverse Osmosis (FO-RO) hybrid desalination technology by figuring out the outlook of the desalination market. Main part of the desalination market will still be MENA (Middle East and North Africa) in the near future due to the fast population increase and high dependency of fossil fuel in the region. The market for FO-RO hybrid technology, however, might be smaller than the conventional SWRO desalination market anyway because of aesthetic issues from using wastewater as raw water and higher costs associated with capex. Therefore, it is essential to improve FO membrane performance and system operation technologies in order to make the hybrid technology attractive compared to the conventional SWRO technology.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.160-160
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• 2022

Floods are the most common natural disasters and are annually causing severe destructions worldwide. Human activities, along with expected increased extreme precipitation patterns as a result of climate change enhance the future potential of floods. There are proven evidence that infrastructure based responses to flood disaster is no longer achieving optimum mitigation and have created a false sense of security. Nature-based solutions(NBS) is a widely accepted sustainable and efficient approach for disaster risk reduction and involves the protection, restoration, or management of natural and semi-natural ecosystems to tackle the climate and natural crisis. Adoption of NBS in decision-making, especially in developing nations is limited due to a lack of sufficient scenario-based studies, research, and technical knowledge. This study explores the knowledge gap and challenges on NBS adoption with case study of developing nation, specially for flood management, by the study of multiple scenario analysis in the context of climate, land-use change, and policies. Identification and quantification of the strength of natural ecosystems for flood resilience and water management can help to prioritize NBS in policymaking leading to sustainable measures for integrated flood management.

• 상하수도학회지
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• 제35권5호
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• pp.335-349
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• 2021

As the frequency of seismic disasters in Korea has increased rapidly since 2016, interest in systematic maintenance and crisis response technologies for structures has been increasing. A data-based leading management system of Lifeline facilities is important for rapid disaster response. In particular, the water supply network, one of the major Lifeline facilities, must be operated by a systematic maintenance and emergency response system for stable water supply. As one of the methods for this, the importance of the structural health monitoring(SHM) technology has emerged as the recent continuous development of sensor and signal processing technology. Among the various types of SHM, because all machines generate vibration, research and application on the efficiency of a vibration-based SHM are expanding. This paper reviews a vibration-based pipeline SHM system for seismic disaster response of water supply pipelines including types of vibration sensors, the current status of vibration signal processing technology and domestic major research on structural pipeline health monitoring, additionally with application plan for existing pipeline operation system.

• 한국농공학회논문집
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• 제63권4호
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• pp.97-104
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• 2021

Despite the practical limitations of calculating the amount of inflow and supply related to the operation of agricultural reservoirs, the role of agricultural reservoirs is gradually being emphasized. In particular, as interest in disaster safety has increased, the demand for preliminary measures to prepare for disasters has been rising, for instance, pre-discharging agricultural reservoirs for flood control. The aim of this study is to analyze the plans for the flood season reservoir operation considering pre-discharge period and water level limit. Accordingly, we optimized the simulation of daily storage using the ratio correction factor (RCFs) and analyzed the amount of inflow and supply using K-HAS. In addition we developed the drought determination coefficient (k) as a indicator of water availability and applied it for supplementing the risk level criteria in the Drought Crisis Response Manual. The results showed that it would be difficult to set the water level limit during the flood period in the situation of little water supply for flood control in agricultural reservoirs. Therefore, it is necessary to operate the reservoir management regulations after measures such as securing additional storage water are established in the future.

• 멤브레인
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• 제32권6호
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• pp.475-485
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• 2022

지속적인 화석연료의 과도한 소비는 지구온난화와 기후환경 위기를 초래하고 있다. 이에 따라 화석연료의 대체 에너지 중 수소에너지가 주목받고 있는데, 수소에너지는 공해물질의 배출이 없고 자원적인 제약이 없다는 장점이 있다. 이에 따라 물의 전기분해를 이용하여 수소를 생산하는 수전해 시스템 및 수소에너지를 연료로 사용하여 전기를 생산하는 연료전지 시스템과 관련된 다양한 연구가 진행되고 있다. 본 연구에서는 수전해 시스템과 연료전지의 핵심 소재 중 하나인 음이온 전도성 이오노머 소재를 대상으로 과량의 수화 상태를 반영하여 3D 이오노머 모델을 제작하였다. 최종적으로 과량의 수화상태에서 이오노머의 구조적인 안정성과 성능 분석을 통해, 수전해 시스템과 연료전지의 핵심 소재인 음이온 전도성 이오노머 설계에 있어서 성능향상 인자를 제시하고자 하였다.

• 문화기술의 융합
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• 제8권5호
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• pp.677-684
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• 2022

본 연구는 창원시 생태환경 지역 평가를 통한 지역 활성화를 위한 기초연구로, 창원시의 생태환경 6곳을 선정하여 저탄소 관광지표를 통해 평가하는 것을 목적으로 한다. 연구대상지는 창원시 6개 생태관광지역이며 각종 문헌자료 및 선행연구를 조사한 후 2021년 6월~7월 직접 방문한 현장조사 및 담당자 면담조사를 통해 생태관광지표를 확인하였다. 생태관광지표는 기후위기, 공기질 개선, 수자원 보전, 자연공존, 시민참여, 관광자원 관리 6가지 부문이다. 창원시 생태관광지역 6곳에 대한 점수를 살펴보면 가장 높게 나타난 것이 자연공존과 공기질 개선 부문이다. 하지만 수자원보전 부문 점수가 가장 낮아 전체 지역이 수자원 보전에 취약하였으며 관광자원 관리, 기후위기, 시민참여는 전체 지역이 비슷한 수준으로 나타났다. 저탄소 생태관광지표를 통해 평가한 결과 공통적으로 적용될 방안으로 첫 번째로, 창원시 저탄소 생태관광 인증제 운영, 자연물 또는 경관 중심의 관광지를 대상으로 인증제도 운영, 스마트 기후환경도시 선포에 따른 후속 조치로써 활용, 환경표지제도를 벤치마킹한 창원시 저탄소 생태관광 등급을 마련하는 것이 필요하다. 두 번째로, 생태관광지역을 활성화하기 위해서는 이에 대한 안내 및 홍보가 매우 중요하다. 마지막으로지속 가능한 지역 생태환경 활성화를 위해서 지역 거버넌스를 활용한 운영이 무엇보다 제고되어야 한다.

• Ocean and Polar Research
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• 제37권1호
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• pp.23-35
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• 2015

A 450 m-long sediment section was recovered from Hole U1359D located at the eastern levee of the Jussieau submarine channel on the Wilkes Land continental rise (East Antarctica) during IODP Expedition 318. The age model for Hole U1359D was established by paleomagnetic stratigraphy and biostratigraphy, and the ages of core-top and core-bottom were estimated to be about 5 Ma and 13 Ma, respectively. Biogenic opal content during this period varied between 3% and 60%. In the Southern Ocean, high biogenic opal content generally represents warm climate characterized by the increased light availability due to the decrease of sea-ice distribution. The surface water productivity change in terms of biogenic opal content at about 10.2 Ma in the Wilkes Land continental rise was related to the development of Northern Component Water. After about 10.2 Ma, more production of Northern Component Water in the North Atlantic caused to increase heat transport to the Southern Ocean, resulting in the enhanced diatom production. Miocene isotope events (Mi4~Mi7), which are intermittent cooling intervals during the Miocene, appeared to be correlated to the low biogenic opal contents, but further refinement was required for precise correlation. Biogenic opal content decreased abruptly during 6 Ma to 5.5 Ma, which most likely corresponds to the Messinian salinity crisis. Short-term variation of biogenic opal content was related to the extent of sea-ice distribution associated with the location of Antarctic Polar Front that was controlled by glacial-interglacial paleoclimate change, although more precise dating and correlation will be necessary. Diatom production in the Wilkes Land continental rise increased during the interglacial periods because of the reduced sea-ice distribution and the southward movement of Antarctic Polar Front.

• 한국수소및신에너지학회논문집
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• 제35권2호
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• pp.162-167
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• 2024

Fossil fuels have been main energy source to people. However, enormous amount of CO₂ was emitted over the world , resulting in global climate crisis today. Recently, solid oxide electrolyzer cell (SOEC) is getting attention as an effective way for producing H₂, a clean energy resource for the future. Also, SOEC could be applicable to reverse water-gas shift reaction process due to its high-temperature operating condition. Here, SOEC system was utilized for both H₂ production and CO₂ reduction process, allowing product gas composition change by controlling operating conditions.

• 유통과학연구
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• 제15권1호
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• pp.83-93
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• 2017

Purpose - After the transition, the development of defense industry in Eastern Europe has been regressed. Recently, they have internationally recognized that new products have been exported and contributed to the Innovation-Based Manufacturing of national economy such as unmanned reconnaissance aircraft, water purification technology, and mobile chemical laboratory, etc. The military forces in Eastern Europe are re-armed by the localization of self-produced munitions in their own defense industry, and then emphasize fostering their own defense industry. Thus, if they make a collaboration with other nations as a industrial cluster, it will gain a competitive edge on the defense industry. Research design, data, and methodology - The study was designed with the data of each national defense department. The research of the subject was reviewed before and after the transition. Thousands of workers have worked in defense industries before the transition, however, the defense industry and experts left after the transition. The Hungarian defense spending on GDP also dropped sharply from 1.72% in 2000 to 0.85% in 2013. But, due to the crisis in Ukraine and the crisis of Syrian refugees, the Viségrad Group (V4) member countries have also increased their interest in a defense and industries as well as the confidence in the EU and NATO. Results - On the whole, the joint of military training and purchase of defense materials were found in order to form the EU cooperative combat troops in CEE. There are the implementation of a joint manual plan for strengthening V4 security policy and the joint military exercises for V4 every year, and the others are electronic warfare and innovation of V4 national forces. Through such a performance analysis methodology, we found that the defense industry is developed through the national cluster cooperation among CEEs and spreading global distribution. Conclusions - Eastern Europe and Balkan countries have been looking forward to cooperating with the non-EU countries such as Korea and other defense industries. There are a lot of potential development into a new civilian cooperation defense industry for global-distribution. Thus, Korea should develop electronic commercial applications, not just as a weapon exporting region.