• International journal of advanced smart convergence
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• 제10권3호
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• pp.41-50
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• 2021

The purpose of this study is to analyze various energy platforms using data in the US and to suggest directions and implications. Some of the leading energy platforms are selected and analyzed based on the opening platform model. We focus on the case analysis of the US utility companies. In case of the horizontal open platform, Green Button sponsor's 'Connect My Data (CMD)' driven by the government invites the utility companies to jointly develop the sponsor's data solution. In case of the vertical open platform, the certification program 'Share My Data (SMD)' allows backward compatibility, because the technical improvement is minimal. The utility companies benchmark Amazon's three-sided market mediation and prefer platform and category exclusivity. For the former, they have data analytics companies like Enervee, Opower and for the latter, they have electronics manufactures and energy service providers (ESPs) like Distributed Energy Resources (DERs). Based on this US case study, we suggest the energy platforms to open their platform for renewable energy supply, energy conservation, high-efficiency products, and residential DER dissemination. To successfully implement the government's energy transition policy, the US platforms should be benchmarked as a business model. Especially, it is needed for them to coordinate a platform ecosystem. To ensure trust in the products and services offered on the marketplace platform, platform's certification program is helpful.

• 한국해양공학회지
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• 제36권6호
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• pp.390-402
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• 2022

Offshore wind energy has become a major energy source, and various studies are underway to increase the economic feasibility of floating offshore wind turbines (FOWT). In this study, the characteristics of wave-induced motion of a combined wind-wave energy platform were analyzed to reduce the variability of energy extraction. A user subroutine was developed, and numerical analysis was performed in connection with the ANSYS-AQWA hydrodynamic program in the time domain. A platform combining the TLP-type FOWT and the Wavestar-type wave energy converter (WEC) was proposed. Each motion response of the platform on the second-order wave load, the effect of WEC attachment and Power take-off (PTO) force were analyzed. The mooring line tension according to the installation location was also analyzed. The vertical motion of a single FOWT was increased approximately three times due to the second-order sum-frequency wave load. The PTO force of the WEC played as a vertical motion damper for the combined platform. The tension of the mooring lines in front of the incident wave direction was dominantly affected by the pitch of the platform, and the mooring lines located at the side of the platform were mainly affected by the heave of the platform.

• 한국해양공학회지
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• 제30권2호
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• pp.84-90
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• 2016

In this study, a six degree-of-freedom motion analysis of a wind-wave hybrid platform equipped with numerous wave energy converters (WECs) was carried out. To examine the effect of the WECs on the platform, an analysis of one-way coupling was carried out, which only considered the power take-off (PTO) damping of the static WECs on the platform. The equation of motion of a floating platform with mooring lines in the time domain was established, and the responses of the one-way coupled platform were then compared with the case of a platform without any coupling effects from the WECs. The hydrodynamic coefficients and wave exciting forces were obtained from the 3D diffraction/radiation pre-processor code WAMIT based on the boundary element method. Then, an analysis of the dynamic responses of the floating platform with or without the WEC effect in the time domain was carried out. All of the dynamics of a floating platform with multiple wind turbines were obtained by coupling FAST and CHARM3D in the time domain, which was further extended to include additional coupled dynamics for multiple turbines. The analysis showed that the PTO damping effect on platform motions was negligible, but coupled effects between multiple WECs and the platform may differentiate the heave, roll, and pitch platform motions from the one without any effects induced by WECs.

• 한국전자통신학회논문지
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• 제13권1호
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• pp.153-162
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• 2018

웨어러블 디바이스의 서비스 제공을 위한 지속 가능한 전원에 대한 요구가 높아짐에 따라 에너지 하베스팅의 중요성이 증대되고 있다. 본 연구는 마찰소자를 고려한 다중 에너지 하베스팅 플랫폼인 EH-P를 개발하였다. 높은 전압과 낮은 전류를 가진 하베스팅 소자에 전압을 낮추면서 전류를 높일 수 있는 스위치 회로 제시하였다. PV와 TENG의 상호보완적 구성을 통해 실내 환경에서 짧은 시간동안 MCU가 동작할 수 있는 전압과 전류를 제공할 수 있었다. 결과적으로 제안된 플랫폼을 통해 웨어러블 플랫폼을 동작시키고, 제작된 웨어러블 디바이스에서 전체 소모 전력 요구량의 29%를 제공함으로써 웨어러블 디바이스 사용시간(device life time)을 증가시킬 수 있었다. 이 논문에 제시된 결과는 멀티플 하베스터 플랫폼에서 웨어러블 하베스팅 애플리케이션의 활용을 위한 발전 소자의 가능성을 보여주었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.73-75
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• 2009

The smart grid which is called the future power system should satisfy the customers who want various choices and realtime energy price. The two-way information exchange platform for energy customers provides the infrastructure to transform today's ESP(Energy Service Provider)-centered power system operation into customer-oriented operation. It enables ESPs to provide their customers with a variety of services by communicating with various appliances in customer's premises. In this paper, the portal-based platform model for the two-way information exchange and its implementation are described.

• Ocean Systems Engineering
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• 제13권4호
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• pp.349-365
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• 2023

Targeting a floating wave and offshore wind hybrid power generation system (FWWHybrid) designed in the Republic of Korea, this study examines the impact of the interaction, with multiple wave energy converters (WECs) placed on the platform, on platform motion. To investigate how the motion of WECs affects the behavior of the FWWHybrid platform, it was numerically compared with a scenario involving a 'single-body' system, where multiple WECs are constrained to the platform. In the case of FWWHybrid, because the platform and multiple WECs move in response to waves simultaneously as a 'multi-body' system, hydrodynamic interactions between these entities come into play. Additionally, the power take-off (PTO) mechanism between the platform and individual WECs is introduced for power production. First, the hydrostatic/dynamic coefficients required for numerical analysis were calculated in the frequency domain and then used in the time domain analysis. These simulations are performed using the extended HARP/CHARM3D code developed from previous studies. By conducting regular wave simulations, the response amplitude operator (RAO) for the platform of both single-body and multi-body scenarios was derived and subsequently compared. Next, to ascertain the difference in response in the real sea environment, this study also includes an analysis of irregular waves. As the floating body maintains its position through connection to a catenary mooring line, the impact of the slowly varying wave drift load cannot be disregarded. To assess the influence of the 2^nd-order wave exciting load, irregular wave simulations were conducted, dividing them into cases where it was not considered and cases where it was included. The analysis of multi-degree-of-freedom behavior confirmed that the action of multiple WECs had a substantial impact on the platform's response.

• Ocean Systems Engineering
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• 제13권4호
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• pp.385-399
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• 2023

A collision between a ship and an offshore platform may result in structural damage and closure; therefore, damage analysis is required to ensure the platform's integrity. This paper presents a damage assessment of a three-legged jacket platform subjected to ship collisions using the industrial finite element program Bentley SACS. This study considers two ships with displacements of 2,000 and 5,000 tons and forward speeds of 2 and 6.17 meters per second. Ship collision loads are applied as a simplified point load on the center of the platform's legs at inclinations of 1/7 and 1/8; diagonal bracing is also included. The jacket platform is modelled as beam elements, with the exception of the impacted jacket members, which are modelled as nonlinear shell elements with elasto-plastic material and constant isotropic hardening to provide realistic dented behavior due to ship collision load. The structural response is investigated, including kinetic energy transfer, stress distribution, and denting damage. The simulation results revealed that the difference in leg inclination has no effect on the level of localized denting damage. However, it was discovered that a leg with a greater inclination (1/8) resists structural displacement more effectively and absorbs less kinetic energy. In this instance, the three-legged platform collapses due to the absorption of 27.30 MJ of energy. These results provide crucial insights for enhancing offshore platform resilience and safety in high-traffic maritime regions, with implications for design and collision mitigation strategies.

• 풍력에너지저널
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• 제13권4호
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• pp.17-25
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• 2022

In this study, the response characteristics of two semi-submersible platforms with an IEA 15 MW reference wind turbine are compared. The nacelle acceleration, platform motion and generator power of FOWT applying a VolturnUS-S platform developed by the University of Maine and PentaSemi platform developed by the Korea Research Institute of Ships and Ocean Engineering are compared in operational conditions. Numerical simulations are performed based on the marine environmental conditions of the U.S east coast. In the FOWT to which the PentaSemi platform is applied, the nacelle acceleration and platform pitch angle are rather high, but the results of both platforms satisfied the design criteria at all operating wind speeds. The platform yaw angle of PentaSemi platform to which a yaw control catenary mooring system is applied is significantly smaller than the platform yaw angle of VolturnUS-S. Also, despite the relatively large nacelle acceleration and platform pitch angle, the generator power is higher on the PentaSemi platform. This means that the generator power dominates the control system rather than the nacelle and platform motion.

• 사물인터넷융복합논문지
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• 제10권2호
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• pp.43-50
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• 2024

본 논문에서는 지구온난화 문제를 해결하기 위해 새로운 에너지원을 만드는 것보다 기존 에너지을 효율적으로 활용하는 인공지능 기반의 에너지 플랫폼 시스템을 제안한다. 이를 위해 공공정보 데이터 포털 및 기상청 데이터를 수집하고 분석하여 최근 5년간 에너지 사용량 및 온실가스 배출량 등 전반적인 에너지 데이터를 전력공급자와 사용자에게 제공하여, 사용자 친화적인 인터페이스를 통해 실시간 에너지 정보 제공 및 효율적인 분산전원 시스템을 제공하고자 한다. 또한 기존 에너지 플랫폼의 한계점을 극복하기 위해 강력한 보안 및 개인정보 보호 기능을 제공하고 있다. 구축된 에너지 플랫폼을 통해 전력 공급자와 사용자의 편의성을 향상 시키고, 불필요한 과잉 전력 생산을 방지하여 지구온난화 문제에 기여하고자 한다. 본 논문에서는 시스템의 설계부터 구현까지의 내용을 상세하게 설명하고, 향후 보완 및 개선 방향을 제시한다.

• 대한전자공학회논문지SD
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• 제41권5호
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• pp.71-80
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• 2004

본 논문은 mobile platform에서 사용될 Multimedia 적용을 위한 embedded Processor의 기본 구조 연구에 관한 내용으로 MPEG4 응용에 적합한 processor의 기본 구조 그리고 mobile platform에 적용될 수 있는 energy efficiency를 고려한 구조설계를 주 내용으로 하고 있다. multimedia 응용 embedded processor의 기본 구현 구조 요소인 processor data path architecture(pipeline, branch prediction, multiple issue superscalar, function unit number)의 기본 구조 설정과 cache hierarchy와 그 구성의 적합한 예상구조를 설정하기 위해 본 논문에서는 multimedia 응용 프로그램인 MPEG4를 processor simulator의 test bench로 사용하여 다양한 구조에 대한 simulation을 수행하였다. 그리고 mobile platform 적용에 적합한 구조인지에 대한 문제를 energy efficiency관점에서 고찰하여 적용 가능한 기본 processor 구조를 설정하였다. 그리고 본 논문에서 제안된 기본 구조 연구는 mobile platform에 바로 적용이 가능하며 더 나아가 특정 응용 프로그램에 최적의 성능을 발휘할 수 있는 자동화 설계기반환경에서의 configurable processor 설계에서 그 기본 processor 구조로 사용될 수 있다.