• International Journal of Computer Science & Network Security
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• 제24권4호
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• pp.87-106
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• 2024

Vehicle-to-Home (V2H) and Home Centralized Photovoltaic (HCPV) systems can address various energy storage issues and enhance demand response programs. Renewable energy, such as solar energy and wind turbines, address the energy gap. However, no energy management system is currently available to regulate the uncertainty of renewable energy sources, electric vehicles, and appliance consumption within a smart microgrid. Therefore, this study investigated the impact of solar photovoltaic (PV) panels, electric vehicles, and Micro-Grid (MG) storage on maximum solar radiation hours. Several Deep Learning (DL) algorithms were applied to account for the uncertainty. Moreover, a Reinforcement Learning HCPV (RL-HCPV) algorithm was created for efficient real-time energy scheduling decisions. The proposed algorithm managed the energy demand between PV solar energy generation and vehicle energy storage. RL-HCPV was modeled according to several constraints to meet household electricity demands in sunny and cloudy weather. Simulations demonstrated how the proposed RL-HCPV system could efficiently handle the demand response and how V2H can help to smooth the appliance load profile and reduce power consumption costs with sustainable power generation. The results demonstrated the advantages of utilizing RL and V2H as potential storage technology for smart buildings.

• 대한원격탐사학회지
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• 제39권6_2호
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• pp.1591-1604
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• 2023

해색 원격탐사에서 대기 보정은 자료의 정확도와 신뢰성 확보를 위해 반드시 수행해야하는 과정으로 높은 정확도가 요구된다. 또한 최근 원격 탐사 커뮤니티에서는 위성 자료의 오차에 대한 요구 사항이 증가함에 따라 대기 보정의 보조 자료로 사용되는 기상 변수(오존량, 기압, 바람장, 층적분 수증기량[total precipitable water, TPW])의 오차에 의해 발생하는 원격 반사도(remote sensing reflectance, R_rs)의 오차에 대한 연구가 진행되고 있지만 오차 요인으로 알려진 수증기 프로파일의 변동성에 의한 R_rs의 오차에 대한 연구는 수행되지 않았다. 본 연구에서는 Second Simulation of a Satellite Signal Vector version 2.1 모의를 통해 GOCI-II 관측 영역 내의 수증기 프로파일의 변동성에 따른 수증기 투과도의 오차를 계산하고 이로 인해 발생하는 해색 산출물의 오차에 대해 분석하였다. Radiosonde 관측 수증기 프로파일은 그 형태가 복잡할 뿐만 아니라 지표 부근의 큰 변동성으로 인해 기존 GOCI-II 대기 보정에서 사용하고 있는 US standard 62 수증기 프로파일과의 차이가 최대 0.007만큼 발생하였다. 이로 인해 발생한 수증기 투과도의 차이는 GOCI-II 대기 보정에서 에어로졸 반사도 추정의 차이를 발생시키고, 결과적으로 모든 밴드에서 R_rs의 오차가 발생하였다. 하지만 412-555 nm 밴드에서 수증기 프로파일 차이로 인한 R_rs 오차는 요구 정확도보다 낮은 2% 미만으로 나타났으며, 다른 해색 산출물인 클로로필(chlorophyll-a) 농도, 용존 유기물, 총 부유물 농도에서도 유사한 오차를 보이고 있다. 본 연구의 결과는 대기 보정 및 해색 산출물의 정확도에 있어 수증기 프로파일의 차이의 영향이 적다는 것을 의미한다. 하지만 추후 연구에서 수증기 흡광 보정 시 수증기 프로파일의 변동성을 고려할 경우 보다 높은 수준의 R_rs 정확도 확보를 기대할 수 있다.

• Ocean Science Journal
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• 제40권1호
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• pp.25-44
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• 2005

Long-term, continuous, and real-time ocean monitoring has been undertaken in order to evaluate various oceanographic phenomena and processes in the East/Japan Sea. Recent technical advances combined with our concerted efforts have allowed us to establish a real-time monitoring system and to accumulate considerable knowledge on what has been taking place in water properties, current systems, and circulation in the East Sea. We have obtained information on volume transport across the Korea Strait through cable voltage measurements and continuous temperature and salinity profile data from ARGO floats placed throughout entire East Sea since 1997. These ARGO float data have been utilized to estimate deep current, inertial kinetic energy, and changes in water mass, especially in the northern East Sea. We have also developed the East Sea Real-time Ocean Buoy (ESROB) in coastal regions and made continual improvements till it has evolved into the most up-to-date and effective monitoring system as a result of remarkable technical progress in data communication systems. Atmospheric and oceanic measurements by ESROB have contributed to the recognition of coastal wind variability, current fluctuations, and internal waves near and off the eastern coast of Korea. Long-tenn current meter moorings have been in operation since 1996 between Ulleungdo and Dokdo to monitor the interbasin deep water exchanges between the Japanese and Ulleung Basins. In addition, remotely sensed satellite data could facilitate the investigation of atmospheric and oceanic surface conditions such as sea surface temperature (SST), sea surface height, near-surface winds, oceanic color, surface roughness, and so on. These satellite data revealed surface frontal structures with a fairly good spatial resolution, seasonal cycle of SST, atmospheric wind forcing, geostrophic current anomalies, and biogeochemical processes associated with physical forcing and processes. Since the East Sea has been recognized as a natural laboratory for global oceanic changes and a clue to abrupt climate change, we aim at constructing a 4-D continuous real-time monitoring system, over a decade at least, using the most advanced techniques to understand a variety of oceanic processes in the East Sea.

• 한국해안해양공학회지
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• 제4권4호
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• pp.208-218
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• 1992

1차원 폐쇄형 수노에서 바람에 의해 발생되는 흐름에 대해 수면구배와 유속의 수직구조를 제시하는 해석해를 정상상태 하에서 유도하였다. 해석해는 저면의 경계조건으로 저면마찰응력 $ au$$_{b}$를 부여하는 가정하에 유도되었으며, 연직 운동양 확산계수 $ extsc{k}$$_{M}$이 수심에 무관한 상수, 수심의 1차함수 및 2차함수일 경우를 포함하며, 저면류속이 no-slip이라는 가정과 저면마찰응력 $\tau$$_{b}$의 매개화에 따른 관계를 제시하고 있다. 모드 분리된, $\sigma$좌표를 채택한 (x-$\sigma$) 수치모형 결과와 유도된 해석해를 비교ㆍ검토하였다. 비교된 경우는 $textsc{k}$$_{M}$이 상수, 수심의 1차 및 2차함수인 경우로써, $textsc{k}$$_{M}$이 상수일 경우는 균일 수심, 완만한 수심경사 및 비교적 급격한 수심경사를 갖는 경우에 대해 수면구배와 유속구조를 검토 하였다. $textsc{k}$$_{M}$이 수심의 1차 및 2차함수인 경우에는 $\tau$$_{b}$의 변화에 대한 유원구조를 비교ㆍ분석하였다. 비교ㆍ분석 결과 유연구조는 $textsc{k}$$_{M}$ 값 뿐만 아니라 $textsc{k}$$_{M}$의 형태에 의해서도 변하며, $\tau$$_{b}$의 간에 의해서도 변하는 것을 보이고 있으며, 계산결과는 전반적으로 해자해와 일치함을 보였다.치함을 보였다.보였다.치함을 보였다.

• 한국해양환경ㆍ에너지학회지
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• 제10권4호
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• pp.193-200
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• 2007

2006년 건기와 우기로 구분하여 연안개발 공사가 이루어지고 있는 해남군 화원면 주변 해역의 15개 정점과 하천 2개 지점 그리고 공사장 배출구 1개 지점에서 pH, 투명도, 염분, SS, DO, COD, ${NH_4}^+$-N, ${NO_2}^-+{NO_3}^-$-N, TN, TP, ${PO_4}^{3-}$-P을 분석한 결과, pH, 투명도, 염분, SS의 경우, 90 mm이상의 집중 강우가 있었던 8월에는 공사장의 배출구와 하천수의 유입구 인근의 해역의 표층수에서 강우에 의한 담수의 유입과 공사장의 배출수의 유입에 의한 영향이 뚜렷하게 나타났다. 하지만 그 외 지점에서는 정점 간, 수층 간 농도 차이가 나타나지 않았다. 예상과 달리 추계 건기에는 강한 바람에 의해 저층으로부터의 침전물질이 부유되어 SS의 농도가 하계의 강우시보다 더 높은 농도를 보였다. 그 외 COD, ${NH_4}^+$-N, TN, TP, ${PO_4}^{3-}$-P의 농도도 유사한 경향을 보였다. 따라서 공사로 인한 연안해역의 수질변화를 평가하기 위해서는 단순히 표층수의 수평적인 조사만으로 그 영향을 평가하기보다는 집중 강우에 의한 영향과 기상이나 해황특성, 침강특성이나 용출특성의 조사를 포함한 SS의 확산시뮬레이션 등으로부터 평가되어야 하겠다.

• Asian Journal of Atmospheric Environment
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• 제8권3호
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• pp.162-174
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• 2014

An abnormal decrease in ozonesonde sensor signal occurred during air-pollution study campaigns in November 2011 and March 2012 in Mexico City Metropolitan Area (MCMA). Sharp drops in sensor signal around 5 km above sea level and above were observed in November 2011, and a reduction of signal over a broad range of altitude was observed in the convective boundary layer in March 2012. Circumstantial evidence indicated that $SO_2$ gas interfered with the electrochemical concentration cell (ECC) ozone sensors in the ozonesonde and that this interference was the cause of the reduced sensor signal output. The sharp drops in November 2011 were attributed to the $SO_2$ plume from Popocat$\acute{e}$petl volcano southeast of MCMA. Experiments on the response of the ECC sensor to representative atmospheric trace gases showed that only $SO_2$ could cause the observed abrupt drops in sensor signal. The vertical profile of the plume reproduced by a Lagrangian particle diffusion simulation supported this finding. A near-ground reduction in the sensor signal in March 2012 was attributed to an $SO_2$ plume from the Tula industrial complex north-west of MCMA. Before and at the time of ozonesonde launch, intermittent high $SO_2$ concentrations were recorded at ground-level monitoring stations north of MCMA. The difference between the $O_3$ concentration measured by the ozonesonde and that recorded by a UV-based $O_3$ monitor was consistent with the $SO_2$ concentration recorded by a UV-based monitor on the ground. The vertical profiles of the plumes estimated by Lagrangian particle diffusion simulation agreed fairly well with the observed profile. Statistical analysis of the wind field in MCMA revealed that the effect Popocat$\acute{e}$petl was most likely to have occurred from June to October, whereas the effect of the industries north of MCMA, including the Tula complex, was predicted to occur throughout the year.

• Nutritional Sciences
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• 제4권2호
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• pp.85-90
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• 2001

The purpose of this study was to evaluate the antioxidative potential of Korean wild leaf vegetables in vivo as well as in vitro. The antloxidative activities of Pleurospemum kamtschaticum, Aderophora remotiflor and Aster gfheni were evaluated as a reference for Spinacia oleracea. Fifty rats were find either a control diet or one of several vegetable diets for 4 weeks. The level of thiobarbituric acid reactive substance (TBARS) and the activity of catalase and superoxide dismutase (SOD) in the liver were compared. The levels of total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and triglyceride (TG) in plasma were also compared. Also, the contents of $\beta$-carotene, vitamin C, vitamin E and total phenolic compound, including flavonoid and thiobarbituric acid (TBA) value using linoleic acid model system, were measured in Korean wind leaf vegetables. The TBARS values of Aderophora remotiflor and Aster giheni tended to be lower than that of Spinacia olerncea. The SOD activity of Artrr glheffi was significantly higher than that of Spinacia oleracea and reached 265% that of the control animals, whereas there was no difference between the control animals and the vegetable diet animals in terms of catalase activity. Compared to the control animals, TG and TC levels were significantly solver and showed a lower artheriosclerotic index. TBA values of Pleurospemum Kamschaticum and Aderophora remptiflor were only 18% of control value. TBA value of Spinacia olerucra was 41% of control value. These results suggest that Aderophora remotinor and Aster glheni could have antioxidative potency in vivo as well as in vitro and potential value far functional flood to improve the plasma lipid profile. flavonoid and phenolic compounds could be the major contributing factor in the antioxidative potential of Aderophora remotiflor and Aster glheni.

• 자원환경지질
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• 제31권6호
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• pp.535-545
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• 1998

Various geophysical methods have been applied to the survey of the lava tunnel of Manjanggul in Cheju Island to study the effectiveness of each method in investigating underground tunnels. The surveys employing gravity, magnetic, electrical, AMT and VLF methods were carried out along seven profiles across the Manjanggul; especially, all the five methods were used on one representative profile. Several aspects of different methods pertinent to their use in investigation of underground tunnels have been noted. The electrical method employing the dipole-dipole array appeared to be the most effective one among five methods. Therefore, we have tested the electrical method more carefully by using various electrode spacings, and obtained successful resistivity sections showing the existence of lava tunnels. The gravity method provided relatively successful responses associated with the tunnel although the gravity readings were contaminated by wind blowing during the survey. The gravity data were also useful for the quantitative modeling study. The magnetic data were also successful in delineating the tunnel qualitatively. The AMT data were not successful because the used frequency band was not appropriate in detecting very shallow target. The VLF data were severely influenced by the neighboring noise sources such as power lines and were not successful in detecting the tunnel responses. The comprehensive result of electrical, gravity and magnetic surveys suggests that undiscovered lava tunnels may exist adjacent to the Manjanggul.

• Structural Engineering and Mechanics
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• 제53권5호
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• pp.881-896
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• 2015

In this study, a method for fatigue performance estimation of deepwater steel catenary riser (SCR) under short-term vortex-induced vibration was investigated for selected S-N curves. General tendency between S-N curve capacity and fatigue performance was analysed. SCRs are generally used to transport produced oil and gas or to export separated oil and gas, and are exposed to various environmental loads in terms of current, wave, wind and others. Current is closely related with VIV and it affects fatigue life of riser structures significantly. In this regards, the process of appropriate S-N curve selection was performed in the initial design stage based on the scale of fabrication-related initial imperfections such as welding, hot spot, crack, stress concentration factor, and others. To draw the general tendency, the effects of stress concentration factor (SCF), S-N curve type, current profile, and three different sizes of SCRs were considered, and the relationship between S-N curve capacity and short-term VIV fatigue performance of SCR was derived. In case of S-N curve selection, DNV (2012) guideline was adopted and four different current profiles of the Gulf of Mexico (normal condition and Hurricane condition) and Brazil (Amazon basin and Campos basin) were considered. The obtained results will be useful to select the S-N curve for deepwater SCRs and also to understand the relationship between S-N curve capacity and short-term VIV fatigue performance of deepwater SCRs.

• 한국대기환경학회지
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• 제2권2호
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• pp.9-18
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• 1986

For identification and apportionment of sources emitting particulate matters in environment, the multi-elemental characterization of size-density fractionated particulate matters was carried out. Eight types of samples were tested; soil, flyash released from burning of bunker-Coil, diesel oil, coal, and soft coal, urban road-way dust, urban dust fall, and airborne particulate matter. The fractions of particulate matters obtained by heavy liquid separation methos with a series of dichloromethane-bromoform were then analyzed using atomic absorption spectrophotometry for Ni, Cr, Cu, An, Fe, Al, and Mg. Each sample showed a different concentration profile as a function of density, and a number of useful conclusions concerning characterization of elemental distribution were obtained. From the density distributions of elements in soil, the maximum value was found for all elements in the density range of 2.2 $\sim 2.9g.cm^{-3}$, including the density of $SiO_2$. However, the distribution of metallic compounds with the density lower than $2.2g.cm^{-3}$ was prevalent in urban roadway dust, urban dust fall, and airborne particulate matter. And the density distribution curves of these urban dusts also have the higher distribution at the density of 2.2 - 2.9g.cm^{-3}$, including the density of wind-blown silica. This tendency generally was prevalent in the natural source elements, such as Al, Fe, Mn, and Mg. The maximum values were found in the density ranges of 1.3 $\sim 2.2g.cm^{-3}$ from the density distribution of elements in oil fired flyash. These distributions of anthropogenic source elements, such as Zn, Ni, Cu, and Cr were higher predominately than those of natural source elements. And the higher distribution was found in the density range of $2.2 \sim 2.9g.cm^{-3}$ from the density distribution of elements in coal and soft-coal fired flyash. These distributions showed similar patterns to soil. But anthropogenic source elements somewhat predominated at the density ranges of $1.3 \sim 2.2g.cm{-3} and 2.9g.cm^{-3}$ to soil. Therefore the higher distribution of anthropogenic source elements in the density ranges of $1.3 \sim 2.2g.cm^{-3} and 2.9g.cm^{-3}$ was considered as anthropogenic origin.