• Korea Trade Review
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• v.43 no.3
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• pp.125-145
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• 2018

The Baltic Shipping Exchange is reporting the Baltic Dry Index (BDI) which represents the average charter rate for bulk carriers transporting major cargoes such as iron ore, coal, grain, and so on. And the current BDI index is reflected in the proportion of capesize 40%, panamax 30% and spramax 30%. Like mentioned above, the capesize plays a major role among the various sizes of bulk carriers and this study is to analyze the influence of the factors influencing on charter rate of capesize carriers which transport iron ore and coal as the major cargoes. For this purpose, this study verified causality between variables using Vector Error Correction Model (VECM) and tried to derive a long-run equilibrium model between the dependent variable and independent variables. Regression analysis showed that every six independent variable has a significant effect on the capesize charter rate, even at the 1% level of significance. Charter rate decreases by 0.08% when capesize total fleet increases by 1%, charter rate increases by 0.04% when bunker oil price increases by 1%, and charter rate decreases by 0.01% when Yen/Dollar rate increases by 1%. And charter rate increases by 0.02% when global GDP increases by one unit (1%). In addition, the increase in cargo volume of iron ore and coal which are major transportation items of capesize carriers has also been shown to increase charter rates. Charter rate increases by 0.11% in case of 1% increase in iron ore cargo volume, and 0.09% in case of 1% increase in coal cargo volume. Although there have been some studies to analyze the influence of factors affecting the charterage of bulk carriers in the past, there have been few studies on the analysis of specific size vessels. At present moment when ship size is getting bigger, this study carried out research on capesize vessels, which are biggest among bulk carriers, and whose utilization is continuously increasing. This study is also expected to contribute to the establishment of trade policies for specific cargoes such as iron ore and coal.

• The Journal of Engineering Geology
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• v.24 no.3
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• pp.423-429
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• 2014

Development of a reservoir pressure core sampler (PCS) with a built-in data logging system (DLS) for recording real-time temperature and pressure observations is critical in domestic hydrocarbon production to accurately measure and monitor reserves of shale gas, coalbed methane, and gas-hydrate. Another purpose of this new technology is to minimize the loss of gas from the core as the drill core is collected. This is accomplished by maintaining the pressure of the sample from the moment the drill core is obtained at depth, thus allowing an accurate analysis of shale gas, coalbed methane gas, and gashydrate within the core. Currently, the United States and European countries have monopolized the development and marketability of PCS technologies. We are thus developing a reservoir PCS by analyzing the operating principle and mechanisms of the existing PCS, and by conducting tests on the existing PCS. We further aim to develop a PCS with a maximum operating pressure of 100 bar, a maximum operating temperature of $-20^{\circ}C$ to $40^{\circ}C$, and a pressure loss rate of 10%.

• Journal of the Korean GEO-environmental Society
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• v.4 no.2
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• pp.15-25
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• 2003

Time Domain Refletometry, or TDR, is a remote sensing electrical measurement technique that has been used for many years to determine the spatial location and nature of various objects, especially in the United States of America and Australia at mining industry. Since early on 1990, the TDR techniques have been applied to the geotechnical engineering such as : deformation measurement of rock slope and landslide, monitoring of ground water content and ground water level change, investigation of ground contamination and its movement. The first application of this technique, in 1996, to the domestic area is to determine the possibility of ground settlement caused by subsidence from abandoned underground mines at the Tongri and Gosari in Gangwon-d. In this paper, through the results of analysed deformation data between conventional measurements and the TDR, it was concluded that the TDR technique is a useful instrumentation method for the prediction of ground deformation.

• Journal of the Korean GEO-environmental Society
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• v.24 no.6
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• pp.5-11
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• 2023

The engineering industry heavily relies on fossil fuels such as coal and petroleum to generate energy through combustion. However, this process emits carbon dioxide into the atmosphere, leading to global warming. To mitigate this issue, researchers have explored various methods to reduce carbon dioxide emissions, one of which is carbon dioxide underground storage technology. This innovative technology involves capturing carbon dioxide from industrial plants and injecting it into the saturated ground layer beneath the earth's surface, storing it securely underground. Despite its potential benefits, carbon dioxide underground storage efficiency needs improvement to optimize storage in a limited space. To address this challenge, our research team has focused on improving storage efficiency by utilizing surfactants. Furthermore, we evaluated how different carbon dioxide states, including gaseous, liquid, and supercritical, impact storage efficiency based on their respective pressures and temperatures within the underground reservoir. Our findings indicate that using surfactants and optimizing the injection rate can effectively enhance storage efficiency across all carbon dioxide states. This research will pave the way for more efficient carbon dioxide underground storage, contributing to mitigating the environmental impact of fossil fuels on the planet.

• Resources Recycling
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• v.24 no.5
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• pp.3-14
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• 2015

This study investigated that status of domestic and international furnace desulfurization and desulfurization characteristics of limestone for fluidized bed use depending on the technology for CFBC one of the CCPs. Limestone-based desulfurizing agent is one of the superior elements which are optimal at around $850-950^{\circ}C$ on high temperature desulfurization. And effectiveness of desulfurization process can be determined by the desulfurization experiment method such as diffusion reaction of the diaphragm of the absorber surface, the size of the particles, the pores of the quantity, size and structure. And, desulfurization efficiency depending on geological and crystallographic properties and calcination process of limestone needs additional research in the future.

• Nuclear industry
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• v.38 no.2
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• pp.13-27
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• 2018

재생에너지의 활용 가능성이 제한적이고 인구 밀도가 높은 대한민국의 현실을 놓고 볼 때, 원자력은 온실가스 배출 및 공해를 줄이면서도 충분한 전력을 생산하여 공급해줄 수 있는 가장 신뢰할만한 발전 수단이다. 그러나 한국 정부는 원전과 석탄발전소를 단계적으로 폐쇄하고 이를 대체하기 위해서 다양한 재생에너지를 늘리겠다는 정책을 확고하게 고수하고 있다. 그렇지만 에너지 생산 수단을 전환하겠다는 이 정책의 주요 목표는 액화천연가스(LNG) 발전을 대체 수단으로 삼고 있다. 그 이유는 다른 재생에너지들의 대규모 생산 수단을 개발하는 데는 기술적이고 경제적인 난제들이 걸림돌이 되기 때문이다. 그러므로 미래의 에너지 정책을 결정하기에 앞서, 에너지 전환 정책의 구체적인 사항들을 확실한 근거에 기반해서 검토한 후 계획을 수립하는 것이 매우 중요한 일이다. 이 문제에 관해서 우리는 다음과 같은 점들을 검토하였다 (1) 한국이 처해 있는 기술적 경제적인 제약을 전제로 한 재생에너지원의 개발에 대한 정부의 역할, (2) 가스 발전으로 인해 발생할 수 있는 환경적이며 경제적인 문제점들, (3) 원전정책을 지속함으로써 얻을 수 있는 이점과 원전 유지에 대한 장애물. 위와 같은 세 가지 사항을 검토한 결과, 한국이 지니고 있는 지리적 경제적인 제약과 함께 탄소 배출로 인해 발생하는 비용까지 효과적으로 줄여야 한다는 점 등을 감안할 때 천연가스 발전으로 집중하겠다는 한국의 미래 에너지 정책은 친환경적이지 못함은 물론 경제적이지도 않기 때문에 적정한 비율의 재생에너지를 포함하는 원전 정책을 지속하는 것만이 현실적인 성공 가능성이 가장 높다고 보는 것이 우리의 결론이다.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.244-249
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• 2011

In this study, performance and economic analysis of 500 MWe coal-fired power plant with $CO_{2}$ capture process was performed. For this purpose, chemical absorption method which is commercially available and most suitable for thermal power plant was studied and a criteria for technical and economic assessment of power plants suggested by IEA Greenhouse Gas R&D Programme was used. And we performed the sensitivity analysis focused on regeneration energy which exceed half of the total capture energy. Based on MEA(Monoethanoleamine) as a main chemical solvent and 3.31 GJ/ton$CO_{2}$ regeneration energy in the stripper, net power efficiency was reduced from 41.0% (no capture) to 31.6%(with capture) and the cost of $CO_{2}$ avoided was estimated 43.3 $/ton$CO_{2}$. And in case of 2.0 GJ/ton$CO_{2}$ regeneration energy, the cost of $CO_{2}$ avoided was calculated as 36.7 $/ton$CO_{2}$.

• Clean Technology
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• v.23 no.4
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• pp.441-447
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• 2017

The economic analysis for the power plant developed in the conceptual design phase is becoming more important and, research on process optimization for process development that meets the target economic is actively carried out. In the filed of power generation systems, economic assessment methods to predict the levelized cost of electricity (LCOE) has been widely applied for comparing economic effect quantitatively. In this paper, the platform that design criteria of key component required to optimize economic of power cycle can be calculated reversely was established roughly and design criteria of the key equipment (Compressor, turbine, heat exchanger) required to meet the target LCOE (the LCOE of supercritical steam Rankine cycle) was derived when the supercritical $CO_2$ power cycle is applied to the coal-fired power plant.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.9-19
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• 2020

An integrated finite element model composed of a boiler and its supporting steel structure for a 375-MW coal-fired power plant was developed. This study used the developed model for seismic analysis using SAP2000 software. For the complex superheaters, reheaters, economizers, and membrane walls of the boiler, which consisted of numerous tubes, a method of modeling them by the equivalent elements in the viewpoint of stiffness and/or inertia was proposed. In addition, a method of modeling for the connection between the boiler and steel structure was proposed. Many hangers that connect the boiler to the girders of a steel structure were transformed into equivalent hangers by decreasing the number. The displacements of the boiler stoppers on the buckstay and the posts of the steel structure were coupled by considering their interface condition. Static analysis under the self-loading condition for the developed integrated model was implemented, and the results of deformation indicated that the behavior of the steel members and the major components of the boiler were appropriate. In conclusion, the integrated model developed in this study can be used to evaluate the safety of the boiler and steel structure under seismic loads.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.2
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• pp.75-97
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• 2000

우리 학회에서는 최근에 폐탄광지 복구에 관한 관심이 고조되고 있으며, 특히 금년내 적당한 시기에, 되도록 빠른 시일 안에 폐탄광지 복구에 관한 국제 심포지엄을 개최할 계획을 가지고 있으나, 아직 학회 설립이후 이 분야에 관한 연구활동이 다소 일천하므로 기초자료준비가 미진한 상태에 있는 현실이다. 이러한 현실적인 상황하에서 필자는 학회의 회장으로서 학회와 회원들의 연구활동지원을 위한 기초적인 자료라도 수집 제공해야 되겠다는 취지를 가지고 이런 저런 일을 진행하고 있다. 이와 같은 학회활동의 하나로 우선 지난 5월 15일부터 20일까지 중국 북경시 신대도(新大都)호텔에서 중국토지학회(中國土地學會) 중국토지부간학회(中國土地復墾學會) 주최로 개최된 "북경 국제토지부간학술연토회(北京 國際土地復墾學術硏討會)" 심포지엄(Beijing International Symposium on Land Reclamation ISLR 2000 - Mine Land Reclamation and Ecological Restoration for 21st Century)에 참석하여 국제적인 상황을 파악할 수 있도록 한 바 있다. 또한 한국의 "폐탄광지역의 산림훼손지 복구 및 폐석유실 방지대책에 관한 고찰" 원고를 우리 학회지에 투고 게재하여 우리 나라의 폐탄광지 복구에 대한 현황을 개략적으로 이해할 수 있도록 하고저 한다. 이와 같은 일을 하다보니, 우리 학회에서도 석탄광산에 관한 전문용어를 파악해야 되겠다는 필요성에 따라서 우선 필자가 가지고 있는 제반 용어자료(참고문헌 제시)를 종합적으로 정리하여 이 용어집을 발표하고자 한다. 이 "소고(小考)" 용어집은 시기적으로 우리 학회 회원들의 필요성에 의해서 편집된 "초고(草稿)" 수준이며, 약 860 용어가 영문 국문(ABC순)/국문 영문(ㄱㄴㄷ순)으로 편집되었다. 이 용어집은 장차 우리 학회에서 용어제정의 기회가 있을 때에는 귀중한 표준 자료로 활용될 수 있을 것이다. 따라서 이 용어집은 우리 학회 제정 표준용어집이 아니라 단순히 필자의 연구자료(안)로 보아야 할 것이다.