• 한국측량학회지
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• 제39권2호
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• pp.113-122
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• 2021

Urban expansion, particularly converting sub-urban areas to residential and commercial land use in metropolitan areas, has been considered as a significant signal of regional economic development. However, this results in urban climate change. One of the key impacts of rapid urbanization on the environment is the effect of UHI (Urban Heat Island). Understanding the effects of urban land cover change on UHI is crucial for improving the ecology and sustainability of cities. This research reports an application of remote sensing data, GIS (Geographic Information Systems) for assessing effects of urban land cover change on the LST (Land Surface Temperature) and heat budget components in Ho Chi Minh City, where is one of the fastest urbanizing region of Vietnam. The change of urban land cover component and LST in the city was derived by using multi-temporal Landsat data for the period of 1998 - 2020. The analysis showed that, from 1998 to 2020 the city had been drastically urbanized into multiple directions, with the urban areas increasing from approximately 125.281 km² in 1998 to 162.6 km² in 2007, and 267.2 km² in 2020, respectively. The results of retrieved LST revealed the radiant temperature for 1998 ranging from 20.2℃ to 31.2℃, while that for 2020 remarkably higher ranging from 22.1℃ to 42.3℃. The results also revealed that given the same percentage of urban land cover components, vegetation area is more effective to reduce the value of LST, meanwhile the impervious surface is the most effective factor to increase the value of the LST.

• 신재생에너지
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• 제18권2호
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• pp.73-81
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• 2022

This study was aimed at designing a condenser, as a component of the organic Rankine cycle system for ships. The condenser was manufactured through press molding to achieve a bent shape to enhance the heat transfer performance, considering the shape of the heat transfer plate used in a brazing plate heat exchanger. The heat transfer plate was made of copper-nickel alloy. The required heat transfer rate for the condenser was 110 kW, and the maximum number of layers was set as 25, considering the characteristics of high-temperature brazing. Computational fluid dynamics techniques were used to perform the thermal fluid analysis, based on the ANSYS CFX (v.18.1) commercial program. The heat transfer rate of the condenser was 4.96 kW for one layer (width and length of 0.224 and 0.7 m, respectively) of the heat transfer exchanger. The fin efficiency pertaining to the heat transfer plate was approximately 20%. The heat flow analysis for one layer of the heat exchanger plate indicated that the condenser with 25 layers of heat transfer plates could achieve a heat transfer rate of 110 kW.

• International Journal of Computer Science & Network Security
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• 제22권10호
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• pp.73-82
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• 2022

Early detection continues to be the mainstay of breast cancer control as well as the improvement of its treatment. Even so, the absence of cancer symptoms at the onset has early detection quite challenging. Therefore, various researchers continue to focus on cancer as a topic of health to try and make improvements from the perspectives of diagnosis, prevention, and treatment. This research's chief goal is development of a system with deep learning for classification of the breast cancer as non-malignant and malignant using mammogram images. The following two distinct approaches: the first one with the utilization of patches of the Region of Interest (ROI), and the second one with the utilization of the overall images is used. The proposed system is composed of the following two distinct stages: the pre-processing stage and the Convolution Neural Network (CNN) building stage. Of late, the use of meta-heuristic optimization algorithms has accomplished a lot of progress in resolving these problems. Teaching-Learning Based Optimization algorithm (TIBO) meta-heuristic was originally employed for resolving problems of continuous optimization. This work has offered the proposals of novel methods for training the Residual Network (ResNet) as well as the CNN based on the TLBO and the Genetic Algorithm (GA). The classification of breast cancer can be enhanced with direct application of the hybrid TLBO- GA. For this hybrid algorithm, the TLBO, i.e., a core component, will combine the following three distinct operators of the GA: coding, crossover, and mutation. In the TLBO, there is a representation of the optimization solutions as students. On the other hand, the hybrid TLBO-GA will have further division of the students as follows: the top students, the ordinary students, and the poor students. The experiments demonstrated that the proposed hybrid TLBO-GA is more effective than TLBO and GA.

• 센서학회지
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• 제31권5호
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• pp.318-323
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• 2022

Barium titanate (BaTiO₃) is considered to be a beneficial ceramic material for multilayer ceramic capacitor (MLCC) applications because of its high dielectric constant and low dielectric loss. Numerous attempts have been made to improve the physical properties of BaTiO₃ in response to recent market trends by employing multicomponent alloying strategies. However, owing to its significant number of atomic combinations and unpredictable physical properties, finding a traditional experimental approach to develop multicomponent systems is difficult; the development of such systems is also time-consuming. In this study, 168 new structures were fabricated using special quasi-random structures (SQSs) of Ba_1-xCa_xTi_1-yZryO₃, and 1680 physical properties were extracted from first-principles calculations. In addition, we built an integrated database to manage the computational results, and will provide big data solutions by performing data analysis combined with AI modeling. We believe that our research will enable the global materials market to realize digital transformation through datalization and intelligence of the material development process.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3150-3163
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• 2023

To improve the performance of blanket: maximizing the tritium breeding rate (TBR) for tritium self-sufficiency, and minimizing the Dose of backplate for radiation protection, most previous studies are based on manual corrections to adjust the blanket structure to achieve optimization design, but it is difficult to find an optimal structure and tends to be trapped by local optimizations as it involves multiphysics field design, which is also inefficient and time-consuming process. The artificial intelligence (AI) maybe is a potential method for the optimization design of the blanket. So, this paper aims to develop an intelligent optimization method based on an improved multi-objective NSGA-III algorithm and an adaptive BP neural network to solve these problems mentioned above. This method has been applied on optimizing the radial arrangement of a conceptual design of CFETR HCSB blanket. Finally, a series of optimal radial arrangements are obtained under the constraints that the temperature of each component of the blanket does not exceed the limit and the radial length remains unchanged, the efficiency of the blanket optimization design is significantly improved. This study will provide a clue and inspiration for the application of artificial intelligence technology in the optimization design of blanket.

• 전자통신동향분석
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• 제38권1호
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• pp.55-64
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• 2023

Recently, preparations for 6G have led to the increasing interest in integrated or hybrid communication networks considering low-orbit satellite communication networks with terrestrial mobile communication networks. In addition, the demand for frequency allocation for new mobile services from low-orbit small satellites to provide global internet of things (IoT) services is increasing. The operation of such satellites and terrestrial mobile communication networks may inevitably cause interference in adjacent bands and the same band frequency between satellites and terrestrial systems. Focusing on the results of the recent ITU-R WP4C meeting, this study introduces the current status of frequency sharing and interference issues between satellites and terrestrial systems, and frequency allocation issues for new mobile satellite operations. Coexistence and compatibility studies with terrestrial IMT in L band and 2.6 GHz band, operated by Inmassat and India, respectively, and a new frequency allocation study (WRC-23 AI 1.18) are carried out to reflect satellite IoT demand. For the L band, technical requirements have been developed for emission from IMT devices at 1,492 MHz to 1,518 MHz to bands above 1,518 MHz. Related studies in the 2 GHz and 2.6 GHz bands are not discussed due to lack of contributions at the recent meeting. In particular, concerning the WRC-23 agenda 1.18 study on the new frequency allocation method of narrowband mobile satellite work in the Region 1 candidate band 2,010 MHz to 2,025 MHz, Region 2 candidate bands 1,695 MHz to 1,710 MHz, 3,300 MHz to 3,315 MHz, and 3,385 MHz to 3,400 MHz, ITU-R results show no new frequency allocation to narrow mobile satellite services. Given the expected various collaborations between satellites and the terrestrial component are in the future, interference issues between terrestrial IMT and mobile satellite services are similarly expected to continuously increase. Therefore, participation in related studies at ITU-R WP4C and active response to protect terrestrial IMT are necessary to protect domestic radio resources and secure additional frequencies reflecting satellite service use plans.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권5호
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• pp.1396-1412
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• 2023

Conversation modeling is an important and challenging task in the field of natural language processing because it is a key component promoting the development of automated humanmachine conversation. Most recent research concerning conversation modeling focuses only on the current utterance (considered as the current question) to generate a response, and thus fails to capture the conversation's logic from its beginning. Some studies concatenate the current question with previous conversation sentences and use it as input for response generation. Another approach is to use an encoder to store all previous utterances. Each time a new question is encountered, the encoder is updated and used to generate the response. Our approach in this paper differs from previous studies in that we explicitly separate the encoding of the question from the encoding of its context. This results in different encoding models for the question and the context, capturing the specificity of each. In this way, we have access to the entire context when generating the response. To this end, we propose a deep neural network-based model, called the Context Model, to encode previous utterances' information and combine it with the current question. This approach satisfies the need for context information while keeping the different roles of the current question and its context separate while generating a response. We investigate two approaches for representing the context: Long short-term memory and Convolutional neural network. Experiments show that our Context Model outperforms a baseline model on both ConvAI2 Dataset and a collected dataset of conversational English.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제12권12호
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• pp.357-362
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• 2023

교량은 중요한 교통 인프라지만 다양한 환경적 요인과 지속적인 교통 부하로 손상 및 균열을 겪게 되며, 이러한 요인들은 교량의 노후화를 가속화시킨다. 현재 건설한 지 오래된 교량이 많아지면서 안전성을 보장하고 노후화를 진단하기 위한 시스템의 필요성이 대두되고 있다. 이미 교량에서는 실시간 또는 주기적으로 교량의 상태를 모니터링하기 위해 구조물 건전도 모니터링(SHM) 기술이 활용되고 있다. 이 기술과 함께 인공지능과 사물인터넷 기술을 활용한 지능형 교량 모니터링 기술 개발이 진행 중이다. 본 논문에서는 노후화된 교량의 유지관리를 위해 고속 푸리에 변환과 차원 축소 알고리즘을 활용한 교량 안전성을 예측 엣지 시스템 기법을 연구한다. 특히, 기존 연구와는 다르게 실제 교량에서 수집된 센서 데이터를 이용하여 데이터셋을 형성하고 교량의 안전성을 확인할 수 있는지 알아본다.

• 한국수산과학회지
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• 제32권1호
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• pp.42-45
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• 1999

미역분말-첨가 미역국수의 지질대사에 미치는 생리적 효능을 구명하기 위하여 SD계 흰쥐에 4주 동안 미역국수 (BA-noodles)를 투여하여 중성지질 (TG), 총콜레스테롤 (TCh), LDL 및 HDL-콜레스테롤, 그리고 동맥경화지수 (AI)에 미치는 BA-noodles의 영향을 평가하였다. SD계 흰쥐에 조제사료로써 4주 동안 사육하면서 $10\%,\;20\%\;40\%$ BA-noodles의 TG의 함량은 $84.78\pm3.52\~91.30\pm3.77$ mg/dl serum로서 대조군 ($99.77\pm4.25$ mg/dl serum: $100\%$ ) 대비 $10\~15\%$정도나 유의적으로 감소하였다. 같은 방법으로 $10\%,\;20\%\;40\%$ BA-noodles의 TCh의 함량은 $87.28\pm4.97\~91.00\pm3.72$ mg/dl serum로서 대조군 ($99.30\pm4.61$ mg/dl serum: $100\%$)대비 $8\~12\%$정도나 유의적으로 감소하였다 또한 $10\%,\;20\%\;40\%$ BA-noodles의 LDL-콜레스테롤의 함량은 $44.20\pm4.21\~46.00\pm4.41$ mg/dl serum으로서 대조군 ($53.75\pm2.18$ mg/dl serum: $100\%$)대비 $15\~18\%$나 유의적으로 감소하였다. 한편 $10\%,\;20\%\;30\%$ BA-noodles 투여군의 HDL-콜레스테롤의 함량은 각각 $25.36\pm1.12\~27.58\pm1.52$ mg/dl serum로서 대조군 ($23.80\pm0.77$ mg/dl serum: $100\%$) 대비 각각 $7\~16\%$정도나 유의적으로 증가하였다. 끝으로 $10\%,\;20\%\;40\%$ BA-noodles 투여군의 AI는 $2.16\pm0.14\~2.59\pm0.17$로서 대조군 ($3.00\pm0.13$ : $100\%$) 대비 $14\~28\%$나 현저히 감소하였다. 이상의 결과에서 볼 때 이들 기능성 미역국수의 투여는 성인병을 효과적으로 억제할 수 있을 것으로 기대된다.

• 한국식품영양과학회지
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• 제36권2호
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• pp.174-179
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• 2007

본 연구는 천마분획물이 본태성고혈압쥐(SHR/NCrj)의 혈압과 혈청지질 농도에 미치는 영향을 평가하기 위하여 수행하였다. 실험은 1기와 2기로 나누어 수행하였는데, 실험 1기는 3주 동안 흰쥐사료에 유지(lard : corn oil : cholesterol=10 : 2 : 1%, w/w)를 첨가한 고지방식이를 급여하였고, 실험 2기는 5주 동안 천마분획물로서 저분자분획(GR-1), 다당체분획(GR-2), 단백질분획(GR-3)을 경구투여하였다. 시험종료 체중은 고지방대조군(D)이 천마분획물군(A, B, C)보다 통계적으로 높았고, 식이섭취량은 D군이 천마분획물군보다 많았으며(p<0.05), 식이효율은 차이가 없었다. 혈청지질 중 총콜레스테롤(TC) 농도는 천마분획물군에서는 비슷하였고, D군이 유의하게 높았다(p<0.05). 중성지방(TG) 농도는 천마분획물중 A군과 B군이 D군에 비해 각각 16, 19% 낮았다. 고밀도지단백-콜레스테롤(HDL) 농도는 다당체분획(B)이 D군에 비해서 각각 21% 높았으며(p<0.05), 저밀도지단백-콜레스테롤(LDL) 농도는 약 25% 정도 낮았다. 동맥경화위험지수(AI)는 천마분획물이 유의하게 낮았고, 특히 다당체분획은 고지방대조군에 비해 42%정도 낮았다(p<0.05). 시험개시후 측정한 기준혈압(RBP)은 $180.0\sim190.0mmHg$로 나타났고, RBP 대비 5주후 혈압은 천마분획물에서 각각 1.7, 5.5, 3.6% 감소한 반면, 고지방대조군(D)은 2.6% 증가하였다. 시험 5주의 고지방대조군 대비 천마분획물의 최종혈압을 비교했을 때 다당체분획(B)이 22 mmHg 낮았다. 이상의 결과에서 천마성분중 특히 다당체분획은 TG를 감소시키는 반면, HDL과 LDL은 각각 증가, 감소시키므로 인해 혈압감소에 유의한 영향을 미친 것으로 사료되었다.