• Ocean Systems Engineering
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• 제13권1호
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• pp.21-41
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• 2023

Decarbonization and energy transition can be considered as a main concern even for the oil industry. One of the initiatives to reduce emissions under studies considers the use of renewable energy as a complimentary supply of electric energy of the production platforms. Wind energy has a higher TRL (Technology Readiness Level) than other types of energy converters and has been considered in these studies. However, other types of renewable energy have potential to be used and hybrid concepts considering wind platforms can help to push the technological development of other types of energy converters and improve their efficiency. In this article, a preliminary hydrodynamic assessment of a new concept of hybrid wind and wave energy conversion platform was performed, in order to evaluate the potential of wave power extraction. A multiple OWCs (Oscillating Water Column) WEC (Wave Energy Converter) design was adopted for the analysis and some simplifications were adopted to permit using a frequency domain approach to evaluate the mean wave power estimation for the location. Other strategies were used in the OWC design to create resonance in the sea energy range to try to maximize the potential power to be extracted, with good results.

• Current Optics and Photonics
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• 제7권5호
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• pp.511-517
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• 2023

Pipelines play an important role in urban water supply and drainage, oil and gas transmission, etc. This paper presents a technique for pattern recognition of fiber optic vibration signals collected by a distributed vibration sensing (DVS) system using a deep learning residual network (ResNet). The optical fiber is laid on the pipeline, and the signal is collected by the DVS system and converted into a 64 × 64 single-channel grayscale image. The grayscale image is input into the ResNet to extract features, and finally the K-nearest-neighbors (KNN) algorithm is used to achieve the classification and recognition of pipeline damage.

• Journal of Nutrition and Health
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• 제29권8호
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• pp.849-860
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• 1996

The supply of different fatty acids during the development period has significant effects. This study examined the effects of dietary $\omega$3 and $\omega$6 fatty acid compositions on phospholipids (PLs) of RBC and rat brain subcellular fractions (synaptosome, microsome, mitochondria), and on learning ability of the 2nd generation rat. Rats were fed experimental diets 3-4 wks prior to the conception. Early in the lactation period, the feeding mothers were exchanged. Diets consisted of 10% fat(by weight), which was either safflower oil('S') poor in $\omega$3 fatty acids or computer-searched mixed oil('M') with P/M/S ratio, 1/1.4/1 and $\omega$6/$\omega$3 ratio, 6.1/1. The 'S' and 'M' rats were subdivided further into SS, SM, MS & MM rats according to their lactation stauts. At 3 (weaning) & 9 wks of age, the percentage of total $\omega$3 fatty acids to their lactation status. At 3 (weaning) & 9 wks of age, the percentage of total $\omega$3 fatty acids and the ratios of $\omega$3/$\omega$6 fatty acids in PLs of RBC and brain subcellular fractions in SM and MM groups fed milk from the mixed oil-fed mothers for 2 wks tended to be higher than those in SS and MS groups respectively. In contrast, the concentrations of $\omega$6 fatty acids, especially 22:5$\omega$6 in all fractions, were significantly lower in the SM & MM groups compared to those of the SS & MS groups respectively. In contrast, the concentration of $\omega$6 fatty acids, especially 22:5$\omega$6 in all fractions, were significantly lower in the SM & MM groups compared to those of the SS & MS groups, The values for the DHA$\omega$3/22:5$\omega$6 ratios after the lactation period were markedly higher in the groups (SM & MM) which were reared by mixed oil(MO) fed mothers. In carring out Y-water maze at 9th wk of age, the SM(4.2$\pm$0.5) & MM (5.3$\pm$0.5) groups made significantly less errors compared to the SS(6.2$\pm$0.6, p<0.05 compared with SM) & MM (7.2$\pm$0.5, p<0.05 compared with MM) groups which were lactated by the safflower oilfed mothers. Therefore, by feeding a balanced fatty acid diet from the lactation period up to 9 wks of age as compared with the groups fed $\omega$3 fatty acid-deficient diet regardless of mother's diet given before parturition. The levels of DHA(synaptosome) and 22:5$\omega$3 (mitochondria) were positively correlated not only with these values in RBC but also with visual discriminating ability. The levels of DHA and 22:5$\omega$3 in RBC can, therfore, reflect visual discriminatng ability in the rat.

• 한국산학기술학회논문지
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• 제19권4호
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• pp.143-153
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• 2018

국제해사기구를 통해 연료유 품질향상 및 배출가스 저감에 대한 논의가 지속되어져 왔다. 국제적으로 가장 큰 관심사 중 하나인 연료유 품질에 대한 사항은 황 함유량 기준이 현행 3.5%에서 2020년까지 0.5%로 한층 더 강화된 규정을 적용하게 되면서 그 관심이 더 증폭되었다. 즉, 연료유의 기본품질은 국내외적인 연료유 정보, 기본성상, 실선 및 함정의 적용을 위한 특성간의 상관성을 포함한 정보사항까지 요구하게 되었다. 이와 관련하여, 국제사회는 연료유의 효율성과 경제성과 관련된 품질 가이드라인의 필요성을 요구하게 되었다. 이러한 흐름과 관련하여, 본 논문에서는 ISO 8217에 의한 기본 연료유 품질분석 결과를 제시하고, 연료의 점화성, 분산성, 기타특성에 대해서 분석하였다. 또한, 실험실 규모의 희석제의 전 후 데이터 결과값이 선박 및 함정의 운항에 적용 가능한 것인지, 기본품질의 상관성이 실선 및 함정에서의 연료의 효율성과 직접적으로 연관성이 있는지 정량분석을 통해서 찾고자 하였다. 물론, 현재의 연료유의 기본품질에 대한 규격이 일반적으로 통용되고 있음에도 불구하고, 연료유의 성상과 조성이 매우 복잡하여 그 기본품질에 대한 해석이 매우 어려운 것은 기본규격의 범위를 벗어나는 경우가 많이 존재하기 때문이다. 결과적으로, 연료유의 기본품질과 선박에서의 운항최적화, 함정에서의 연료 효율이라는 측면에서 연료유의 기본품질에 대해서 다양한 인자들을 분석하였고, 희석에 따른 그 기준의 적용 범위에 대해서 가능성을 제시하고자 하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권6호
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• pp.820-826
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• 2013

The objective of this study was to determine the effect of rain tree pod meal with palm oil supplementation on feed intake, digestibility, microbial protein synthesis and microbial populations in dairy cows. Four, multiparous early-lactation Holstein-Friesian crossbred (75%) lactating dairy cows with an initial body weight (BW) of $405{\pm}40$ kg and $36{\pm}8$ DIM were randomly assigned to receive dietary treatments according to a $4{\times}4$ Latin square design. The four dietary treatments were un-supplementation (control), supplementation with rain tree pod meal (RPM) at 60 g/kg, supplementation with palm oil (PO) at 20 g/kg, and supplementation with RPM at 60 g/kg and PO at 20 g/kg (RPO), of total dry matter intake. The cows were offered concentrates, at a ratio of concentrate to milk production of 1:2, and chopped 30 g/kg of urea treated rice straw was fed ad libitum. The RPM contained condensed tannins and crude saponins at 88 and 141 g/kg of DM, respectively. It was found that supplementation with RPM and/or PO to dairy cows diets did not show negative effects on feed intake and ruminal pH and BUN at any times of sampling (p>0.05). However, RPM supplementation resulted in lower crude protein digestibility, $NH_3$-N concentration and number of proteolytic bacteria. It resulted in greater allantoin absorption and microbial crude protein (p<0.05). In addition, dairy cows showed a higher efficiency of microbial N supply (EMNS) in both RPM and RPO treatments. Moreover, NDF digestibility and cellulolytic bacteria numbers were highest in RPO supplementation (p<0.05) while, supplementation with RPM and/or PO decreased the protozoa population in dairy cows. Based on this study, supplementation with RPM and/or PO in diets could improve fiber digestibility, microbial protein synthesis in terms of quantity and efficiency and microbial populations in dairy cows.

• 생명과학회지
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• 제31권8호
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• pp.778-785
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• 2021

오이 씨앗의 발아는 세포의 지방체내 저장지방의 분해 결과인 acyl-CoA의 글라이옥시좀으로 이동 후 베타 산화의 결과물인 acetyl-CoA의 글라이옥실산 회로로의 유입과 지방의 유동으로 촉발된다. Acetyl-CoA는 글라이옥실산 회로의 가동을 위한 탄소원을 제공하며 시트르산과 말산을 생성하며 글라이옥실산 회로의 작동을 유도한다. 지방 저장 종자의 발아에 있어서 글라이옥실산 회로는 필수적 요소이며, 그 결과물인 말산 및 숙신산의 미토콘드리아로의 이동은 TCA 회로의 가동과 옥살초산의 생성 및 세포질로의 유동으로 PEPCK에 의한 당신생을 가능하게 한다. 즉, 저장 지방을 원료로 여러 대사물질의 생산 및 이동과 다중의 대사경로를 통하여 발아 시 사용 가능한 에너지원인 포도당의 형태로 전환이 이루어진다. 이에 동반하여 많은 유전자의 발현 조절이 이루어지고, 세포내 소기관 특히 미소체로 대표되는 글라이옥시좀은 말산 합성효소(malate synthase)와 이소 시트르산 분해효소(isocitrate lyase)로 특화된다. 또 다른 acetyl-CoA의 유동은 carnitine을 매개로 하는 BOU (A BOUT DE SOUFFLE)의 작동이다. 이것은 카니틴의 대사와 관련하여 고등식물의 발달과 대사과정에서의 중요성이 확인된 것으로 사료된다.

• Animal Bioscience
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• 제36권2호
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• pp.256-263
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• 2023

Objective: Feed molecular structures can affect its availability to gastrointestinal enzymes which impact its digestibility and absorption. The molecular spectroscopy-attenuated total reflectance Fourier transform infrared vibrational spectroscopy (ATR-FTIR) is an advanced technique that measures the absorbance of chemical functional groups on the infrared region so that we can identify and quantify molecules and functional groups in a feed. The program aimed to reveal the association of intrinsic molecular structure with nutrient supply to animals from canola feedstocks and co-products from bio-oil processing. The objective of this study was to characterize special intrinsic carbohydrate and protein-related molecular structure spectral profiles of feedstock and co-products (meal and pellets) from bio-oil processing from two source origins: Canada (CA) and China (CH). Methods: The samples of feedstock and co-products were obtained from five different companies in each country arranged by the Canola Council of Canada (CCC). The molecular structure spectral features were analyzed using advanced vibrational molecular spectroscopy-ATR-FTIR. The spectral features that accessed included: i) protein-related spectral features (Amide I, Amide II, α-helix, β-sheet, and their spectral intensity ratios), ii) carbohydrate-related spectral features (TC1, TC2, TC3, TC4, CEC, STC1, STC2, STC3, STC4, TC, and their spectral intensity ratios). Results: The results showed that significant differences were observed on all vibrationally spectral features related to total carbohydrates, structural carbohydrates, and cellulosic compounds (p<0.05), except spectral features of TC2 and STC1 (p>0.05) of co-products, where CH meals presented higher peaks of these structures than CA. Similarly, it was for the carbohydrate-related molecular structure of canola seeds where the difference between CA and CH occurred except for STC3 height, CEC and STC areas (p>0.05). The protein-related molecular structures were similar for the canola seeds from both countries. However, CH meals presented higher peaks of amide I, α-helix, and β-sheet heights, α-helix:β-sheet ratio, total amide and amide I areas (p<0.05). Conclusion: The principal component analysis was able to explain over 90% of the variabilities in the carbohydrate and protein structures although it was not able to separate the samples from the two countries, indicating feedstock and coproducts interrelationship between CH and CA.

• 한국전기전자재료학회논문지
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• 제35권6호
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• pp.631-638
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• 2022

Microgrid, which enables the production and consumption of electricity to be done independently on a small scale, has been studied on one of the solutions of reinforcement for flexibility of electronic system. This study examined the application effect of new microgrid by applying hybrid battery in electric power storage device. We designed the system to highlight the advantage of each battery and complement the disadvantage by using hybrid system with Lithium-ion battery and interval Redox flow battery. It runs with lithium-ion battery during the initial startup while the Redox flow battery operates for a long time at the end of excessive period, and it enables a discharge of Lithium-ion and Redox flow battery at the same time when the load has a large output. We chose Maldives as a subject of this study for organizing and optimizing independent microgrid. Maldives is the country to accomplish 100% domestic electricity in South Asia, but the whole electric power is supplied through diesel generation imported fossil fuel. We organized and optimized microgrid for energy independence on Malahini island to solve Maldives energy cost problem and global energy environment matters. We analyzed the daily power supply and accumulated the power supply from September 18, 2018~February 11, 2019. The accumulated power supply was about 120.4 MWh and the daily power supply was about 800~1000 kWh. Based on the collected information, we divided the cases into three models which are only diesel generator, solar generator as well as diesel generator, and solar+ESS+diesel generator. We analyzed the amount of oil consumption compared to the cost of construction and power output. The result showed that solar+ESS+diesel generator was most economically feasible. As well, we obtained that our considering hybrid battery system reduced the fuel consumption for diesel power generation about 10~15%.

• 에너지공학
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• 제22권4호
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• pp.376-385
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• 2013

에너지부문의 가격인상이 물가에 미치는 영향에 대해 정부, 공급자, 수용가 사이에 논란이 존재한다. 공급자는 만성적자 해소와 경영의 계속성을 근거로 에너지요금 인상을 추진하지만 이에대해 한편에서는 물가상승 우려로 인한 반대의 목소리도 있다. 이러한 배경하에서 본 논문은 주요 에너지원별 가격변동의 물가파급효과를 정량적으로 규명하고자 한다. 이를 위해 2011년 산업연관표에 근거한 투입산출 분석을 적용하여 석탄, 나프타, 휘발유, 등유, 경유, 중유, LPG, 전력, 도시가스, 증기 및 온수공급업 총 10개 에너지원별 물가파급효과를 분석한다. 물가파급효과분석을 위해 레온티에프 가격모형을 적용하였고 분석결과 에너지원별로 요금을 10% 인상할 경우, 전력부문이 0.2196%로 10개 에너지원 중 물가파급효과가 가장 높게 나타났다. 반면 등유는 0.0122%로 10개 에너지원 중 가장 낮은 물가파급효과를 보였다. 가장 낮은 물가파급효과를 보이는 등유에 비해 가장 높은 물가파급효과를 보였던 전력부문은 약 18배의 물가파급효과가 있는 것으로 분석되었다. 더 나아가 10개의 에너지원별 물가파급효과에 대해 최근 3년의 결과를 비교하였고, 각각의 에너지원별로 가격을 조정하여 국민경제 전체로는 물가중립을 유지하는 자료로 제시하였다.

• 한국환경농학회지
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• 제38권4호
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• pp.262-268
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• 2019

토양에서 유기자원의 무기화 특성을 구명하기 위하여 질소함량별로 볏짚, 우분퇴비, 균배양체, 유박, 아미노볼 등 총 5가지를 각각 처리하여 128일 동안 실내 항온배양실험을 실시하였으며, 이 분석결과를 질소 무기화 모형에 적용하여 유기자원의 질소 무기화 양상을 구명하였다. 항온배양 기간 동안 유기자원의 질소 순 무기화율은 질소함량이 가장 높은 아미노볼에서 가장 높았고, 질소함량이 가장 낮은 볏짚에서 가장 낮았다.잠재적 질소 무기화율은 전질소 함량과는 양의 상관관계(0.96)가 인정되었다. 무기화 속도상수 k는 유기자원의 유기물(-0.96) 및 탄소함량(-0.97)과 음의 상관관계가 인정되었다. 모형에 의해 추정된 1작기 동안의 질소 무기화율은 볏짚 6.6%, 우분퇴비 11.6%, 균배양체 30.9%, 유박 70.7%이었으며 아미노볼은 81.0%를 나타냈다. 질소 무기화율은 유기자원의 종류 또는 질소함량에 따라 다르게 나타나 질소 무기화율을 유기자원의 질소 공급 특성을 결정하는 지표로 사용할 수 있다. 질소함량이낮거나 발효과정을 거치는 퇴비 등의 유기자원은 퇴비화 과정에서 유기태 질소가 안정화되어 질소의 무기화율이 무발효 유기자원보다 낮으므로 시비량 결정시 양분공급의 목적보다는 토양 물리성 개량을 목적으로 사용하는 것이 바람직하다.