• Proceedings of the Korean Society of Disaster Information Conference
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• 2017.11a
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• pp.105-106
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• 2017

현대의 도시재생사업은 도시의 기존 모습을 유지하면서도 낙후된 도심 환경을 개선하여 원주민의 재정착률을 높이고 쇠퇴한 구도심에 새로운 활력을 불어넣는 것을 목표로 한다. 도시재생에서 환경조형물은 이러한 시대적 요구와 그것이 놓이는 장소 혹은 공간이 가지는 의미, 공공성 또는 공익성이라는 영역에서 예술적 가치를 창출해야 한다. 이 논문에서는 마을흔적보전사업의 환경조형물을 '리사이클, 업사이클, 뉴사이클'이라는 3개 유형으로 나누어 살펴본다. 이를 통해 환경조형물이 예술적 가치뿐만 아니라 마을흔적보전이라는 사회적 역사적 문화적 가치를 담아냄으로서 도시재생이 가지고 있는 목표를 실현하는 중요한 요소가 될 수 있음을 알 수 있다.

• Journal of Energy Engineering
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• v.18 no.2
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• pp.93-100
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• 2009

An exergy analysis is carried out for the regenerative wet-compression Brayton cycle which has a potential of enhanced thermal efficiency owing to the reduced compression power consumption and the recuperation of exhaust energy. Using the analysis model, the effects of pressure ratio and water injection ratio are investigated on the exergy efficiency of system, exergy destruction ratio for each component of the system, and exergy loss ratio due to exhaust gas. The results of computation for the typical cases show that the regenerative wet-compression gas turbine cycle can make a notable enhancement of exergy efficiency. The injection of water results in a decrease of exergy loss of exhaust gas and an increase of net power output.

• Journal of the Korean Institute of Gas
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• v.3 no.1
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• pp.14-20
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• 1999

This study describes the results of Coefficient of Performance(COP) analysis by cycle simulation for two types of absorption-compression hybrid cycle using the Water/Lithium Bromide solution pair. These types are basic hybrid systems introducing a mechanical compression process into the refrigerant vapor phase of the single effect absorption cycle. In absorption-compression hybrid cycles, coefficient of performance is improved compared with absorption cycle. Hybrid cycle Type 2 is considered as a key technology to support energy utilization system, given its capability of utilizing waste heat to drive system with a high level of efficiency.

• Resources Recycling
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• v.24 no.5
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• pp.22-32
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• 2015

This study aims to discuss the concept of upcycling as it applies to diaper recycling. Upcycling is the process of converting waste materials into new products of better quality. Through benchmarking of upcycling examples, useless objects can be transformed into valuable materials. However, current upcycling examples determine value creation related to qualitative elements, so that it is difficult to establish any quantitative strategy of upcycled products. Therefore, this study expands a B2B (Business to business) product for improving market availability and establishes a direction using both recovered pulp and mixed plastic at the same time. As a result, the upcycling method for recovered pulp and mixed plastics, is the application of a cellulose insulator. Within the near future, the high quality insulator market will grow more than three times. An upcycling strategy targeting the high quality insulator market needs to be established.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.2
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• pp.116-121
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• 2014

In order to study the improvement of the multi stage regeneration cycles, muti-stage processes were applied to the cycles, respectively or together. The kinds of the cycles are multi stage reheater cycle (MS) and multi stage reheater regeneration cycle (MSR). Working fluid used was R134a and R245fa. Temperature of the heat source was $65^{\circ}C$, $75^{\circ}C$, and $85^{\circ}C$, and temperature of the heat sink was $5^{\circ}C$. Optimization simulation was conducted for improving the gross power and efficiency with multi stage reheater regeneration cycle for ocean thermal energy conversion(OTEC) with changing of a heat source, kind of the working fluid, and type of the cycle. Performance analysis of the various components was simulated by using the Aspen HYSYS for analysis of the thermodynamic cycle. R245fa shows better performance than R134a. This paper showed the most suitable working fluid with changing of a heat source and the kinds of working cycle. Compared to each other, MS showed better performance at gross power and MSR showed higher cycle efficiency.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.8
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• pp.1151-1157
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• 2012

Ocean Thermal Energy Conversion(OTEC) technology is one of the new and renewable energy that utilizes the natural temperature gradient that exists in the tropical ocean between warm surface water and the deep cold water, to generate electricity. The selection of working fluid and the OTEC cycle greatly influence the effect on the system operation, and it's energy efficiency and impacts on the environment. Working fluids of the OTEC are ammonia, R22, R407C, and R410A. In this paper, we compared boiling pressure to optimize OTEC system at $25^{\circ}C$. Also, this paper showed net-power and efficiency according to working fluids for closed cycle and regeneration cycle.

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.177-178
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• 2018

업사이클링 산업은 관련 국내 시장의 규모가 해외 시장보다 현저히 느려 미약적인 성장을 거듭하였지만 2016년 기준 약 200억원까지 달하는 것으로 분석되어 관련 사업이 지속적으로 발전할 것으로 예상된다. 역사성을 지속시키되 창의성을 더한 희소성, 친환경 의식으로 감성적 '가치소비' 트렌트와 맞물리면서 업사이클링 산업은 확산될 것으로 기대된다. 이에 따라 업사이클링 시장 환경을 되살리고 새로운 부가가치를 창출하는 새로운 신 시장으로 다가오고 있다. 이러한 배경에서 본 연구는 국 내외 업사이클링을 기반으로 한 도시재생 사례를 분석하는 연구로서 이를 통해 공공 환경 디자인에 업사이클링이 적용될 수 있는 기초 연구로서 의의가 있다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.9
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• pp.589-596
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• 2016

Recently organic flash cycle (OFC) has been proposed which is a vapor power cycle where heat addition occurs with the working fluid remaining in the liquid state. This study proposes a modified OFC with regeneration and carries out thermodynamic performance analysis of the system utilizing low-temperature heat source in the form of sensible energy. Effects of working fluid and flash temperature are systemically investigated on the system performance such as net power production and thermal efficiency. Results show that the net power production has a peak value with respect to the flash temperature but the thermal efficiency increases with the flash temperature. The regenerative system shows higher thermal efficiency compared to the original OFC and improved potential for recovery of low-temperature heat sources.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.46-52
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• 2011

A study on the improvement for cycle efficiency of closed-type ocean thermal energy conversion (OTEC) was studied to obtain the basic data for the optimal design of cycle. For that, OTEC cycle with a generator, a reheater and a multi-turbine was simulated and analyzed. The basic thermodynamic model for OTEC is Rankine cycle and the surface seawater of $26^{\circ}C$ and deep seawater of $5^{\circ}C$ were used for the heat source of evaporator and condenser, respectively. Ammonia is used as the working fluid. The cycle efficiency increased when generator is added with 0.9 generator effectiveness. When the reheater and multi-turbine are applied in the basic cycle, the cycle efficiency showed 3.14% and the capacity of heat exchanger decreased for same total cycle power. For the OTEC cycle with the generator, the reheater and the multi-turbine showed the highest cycle efficiency and increased the efficiency by more than 6.5% comparing with the basic OTEC cycle.

• Journal of the Korean Electrochemical Society
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• v.15 no.3
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• pp.160-164
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• 2012

The lead-acid batteries are the most often used in human life, because of their low cost, good reversibility and high potential but they have limit cycle ability with low capacitance. The main causes of this problem are forming recrystallization of $PbSO_4$ on electrodes surface during cycles which the recrystallization of $PbSO_4$ is known as sulfation. In this study, formation process of sulfation was investigated depending on charge and discharge cycle numbers. And we decomposed sulfation to renew cycle ability of lead-acid batteries. The renewed lead-acid batteries recovered to 84% compared to first capacity after 600 cycles.