• International Journal of Computer Science & Network Security
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• 제22권2호
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• pp.214-222
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• 2022

Convolutional Neural networks (CNNs) are a category of deep learning networks that have proven very effective in computer vision tasks such as image classification. Notwithstanding, not much has been seen in its use for remote sensing image classification in developing countries. This is majorly due to the scarcity of training data. Recently, transfer learning technique has successfully been used to develop state-of-the art models for remote sensing (RS) image classification tasks using training and testing data from well-known RS data repositories. However, the ability of such model to classify RS test data from a different dataset has not been sufficiently investigated. In this paper, we propose a deep CNN model that can classify RS test data from a dataset different from the training dataset. To achieve our objective, we first, re-trained a ResNet-50 model using EuroSAT, a large-scale RS dataset to develop a base model then we integrated Augmentation and Ensemble learning to improve its generalization ability. We further experimented on the ability of this model to classify a novel dataset (Nig_Images). The final classification results shows that our model achieves a 96% and 80% accuracy on EuroSAT and Nig_Images test data respectively. Adequate knowledge and usage of this framework is expected to encourage research and the usage of deep CNNs for land cover mapping in cases of lack of training data as obtainable in developing countries.

• Geomechanics and Engineering
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• 제27권6호
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• pp.537-550
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• 2021

There are various technical problems need to be solved in the construction process of pre-setting an isolation wall into a double lane in the outburst prone mine. This study presents a methodology that pre-setting an isolation wall into a double lane without a coal pillar. This requires the excavation of two small section roadways to dig a wide section roadway, followed by construction of the separation wall. During this process the connecting lane is reserved. In order to ensure the stability of the separation wall, the required bearing capacity of the isolation wall is 4.66 MN/m and the deformation of the isolation wall is approximately 25 cm. To reduce the difficulty of implementing support the roadway is driven by 5 m/d. After the construction of the separation wall, the left side coal wall is brushed 1.5 m to make the width of the gas roadway reach 2.5 m and the roadway support utilizes anchor rod, ladder beam, anchor cable beam and net configuration. During construction, the concrete pump and removable self-propelled hydraulic wall mold are used to pump and pour the concrete of the isolation wall. In the process of mining, the stress distribution of coal body and isolation wall is detected and measured on site. The results demonstrate that the deformation of the surrounding rock of roadway and separation of roof in the roadway is small. The stress of the bolt and anchor cable is within equipment tolerance validating their selection. The roadway is well supported and the intended goal is achieved. The methodology can be used for reference for similar mine gas control.

• Nuclear Engineering and Technology
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• 제53권12호
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• pp.4106-4113
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• 2021

Rare earth doped barium tellurite glasses were synthesised and explored for their radiation shielding applications. All the samples showed good thermal stability with values varying between 101 ℃ and 135 ℃ based on dopants. Structural properties showed the dominance of matrix elements compared to rare earth dopants in forming the bridging and non-bridging atoms in the network. Bandgap values varied between 3.30 and 4.05 eV which was found to be monotonic with respective rare earth dopants indicating their modification effect in the network. Various radiation shielding parameters like linear attenuation coefficient, mean free path and half value layer were calculated and each showed the effect of doping. For all samples, LAC values decreased with increase in energy and is attributed to photoelectric mechanism. Thulium doped glasses showed the highest value of 1.18 cm^-1 at 0.245 MeV for 2 mol.% doping, which decreased in the order of erbium, holmium and the base barium tellurite glass, while half value layer and mean free paths showed an opposite trend with least value for 2 mol.% thulium indicating that thulium doped samples are better attenuators compared to undoped and other rare earth doped samples. Studies indicate an increased level of thulium doping in barium tellurite glasses can lead to efficient shielding materials for high energy radiation.

• Nuclear Engineering and Technology
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• 제53권12호
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• pp.4114-4121
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• 2021

The Rooppur Nuclear Power Plant (RNPP), the first nuclear power plant in Bangladesh with a capacity of 2.4 GWe, is under construction on the bank of the river Padma, at Rooppur in Bangladesh. Measurement of background radioactivity in the natural environment adjacent to RNPP finds great importance for future perspectives. Soil and sediment samples collected from upstream and downstream positions of the Padma River (adjacent to RNPP) were collected and analyzed by HPGe gamma-ray spectrometry for primordial radionuclides. The average activity concentrations (in Bqkg^-1) of ²²⁶Ra, ²³²Th and ⁴⁰K radionuclides in soil samples were found to be 44.99 ± 3.89, 66.28 ± 6.55 and 553 ± 82.17 respectively. Respective values in sediment samples were found to be 44.59 ± 4.58, 67.64 ± 7.93, 782 ± 108. Relevant radiation hazard indices and dosimetric parameters were calculated and compared with the world average data recommended by US-EPA. Analytical results show non-negligible radiation hazards to the surrounding populace. Measured data will be useful to monitor any change of background radioactivity in the surrounding environment of RNPP following its operation for the generation of nuclear energy.

• Nuclear Engineering and Technology
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• 제55권8호
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• pp.3054-3070
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• 2023

Nuclear Power Plants (NPP) are widely utilized around the globe from different base forms as it is one of the most dependable renewable resources that technological advancements have offered. However, different perceptions of the usage of NPPs emerged from different generations. The purpose of this study was to investigate the acceptance of nuclear energy as an alternative source of energy among Generation Z in the Philippines by utilizing an extended Theory of Planned Behavior (TPB) approach. An online questionnaire which consisted of 31 items was distributed using a purposive sampling approach and 450 respondents of Generation Z voluntarily answered. Structural Equation Modeling (SEM) showed that the knowledge regarding NPP had significant effects on risk perception and benefit perception which subsequently led to subjective norms. In addition, perceived behavioral control and subjective norms had significant effects on behavioral intention which led to nuclear acceptance. Interestingly, the respondents perceived the benefit of NPP as slightly higher than the perceived risk. With these, it was clear that the commissioning Nuclear Power Plant must consider as an alternative source of electric energy in the Philippines. Moreover, this study is one of the first studies that investigated the acceptance of NPP among Generation Z. Lastly, the model could be a basis to strengthen the acceptance strategy of opening NPP among Generation Z, particularly in developing countries.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4072-4083
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• 2022

Ultrasonic impact treatment (UIT) is carried out on the Ni-based alloy stainless steel pipe gas tungsten arc welding (GTAW) girth weld, the differences of microstructure, microhardness and shear strength distribution of the joint before and after ultrasonic shock are studied by microhardness test and shear punch test. The results show that after UIT, the plastic deformation layer is formed on the outside surface of the Ni-based alloy overlayer, single-phase austenite and γ type precipitates are formed in the overlayer, and a large number of columnar crystals are formed on the bottom side of the overlayer. The average microhardness of the overlayer increased from 221 H V to 254 H V by 14.9%, the shear strength increased from 696 MPa to 882 MPa with an increase of 26.7% and the transverse average residual stress decreased from 102.71 MPa (tensile stress) to -18.33 MPa (compressive stress), the longitudinal average residual stress decreased from 114.87 MPa (tensile stress) to -84.64 MPa (compressive stress). The fracture surface has been appeared obvious shear lip marks and a few dimples. The element migrates at the fusion boundary between the Ni-based alloy overlayer and the austenitic stainless steel joint, which is leaded to form a local martensite zone and appear hot cracks. The welded joint is cooled by FA solidification mode, which is forming a large number of late and skeleton ferrite phase with an average microhardness of 190 H V and no obvious change in shear strength. The base metal is all austenitic phase with an average microhardness of 206 H V and shear strength of 696 MPa.

• 한국어류학회지
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• 제34권4호
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• pp.225-230
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• 2022

2020년 11월 한국 제주도 남부에서 봉고네트로 채집된 놀래기과 고생놀래기속 후기자어 1개체를 형태 분석한 결과, Thalassoma quinquevittatum로 확인되었다. 자치어 시기에 형태적으로 매우 유사한 색동놀래기 T. amblycephalum와 등쪽 경사, 눈의 모양, 흑색소포의 분포에서 구별된다. 미토콘드리아 DNA COI 염기서열 548 bp을 분석한 결과, T. quinquevittatum 성어와 0.2~0.5% 유전적 차이를 보였고, 같은 속의 T. amblycephalum, T. cupido, T. lunare, T. purpureum, T. lucasanum, T. lutescens와는 각각 12.3%, 13.7%, 13.2%, 12.1%, 13%, 11.2%의 유전적 차이를 보였다. 국내 처음 보고되는 본 종의 새로운 국명으로 "다섯줄색동놀래기"를 제안한다.

• 한국어류학회지
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• 제35권1호
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• pp.57-63
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• 2023

본 연구에서는 2018년 2~3월 제주도 남부해역에서 Bathylagidae에 속하는 Lipolagus ochotensis 자어 4개체(체장 13.4~21.3 mm)를 봉고네트로 채집하였다. L. ochotensis 자어는 몸이 길게 신장되었으며, 체고는 낮고, 눈이 돌출되며, 몸의 후반부에 흑색소포가 나 있고, 등지느러미가 몸 중앙에 위치하는 특징을 가진다. 미토콘드리아 DNA COI의 염기서열 625 bp를 분석한 결과, L. ochotensis 성어와 97.6%로 매우 가깝게 나타났다. 국내 처음 보고되는 본 종의 새로운 과명으로 "심해빙어과", 속명으로 "검은빙어속", 국명으로 "검은뺨빙어"를 각각 제안한다.

• 한국토양비료학회지
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• 제45권6호
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• pp.904-909
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• 2012

황철석 (Pyrite, FeS2)을 함유한 잠재특이산성토는 강하류 삼각지 토양, 간척지 등의 해성토뿐만 아니라, 영일만과 같은 융기해성토 지대, 내륙의 선상지하단 유기물이 많은 암흑색 토층이 있을 때에 존재하는 수가 있다. 또한 안산암 지역의 열수작용에 의해 생성되어 암맥을 따라 형성된 황철석이 광산개발이나 도로건설로 절취사면에서 노출되어 산화되면 매우 강한 산성을 띠는 특이산성토층을 형성하여 주변농경지에 피해를 주고 있다. 현재 잠재특이산성토양의 판정은 현장에서는 과산화수소로 반응 시 수증기발생 정도로 판단하거나 실내실험에서는 전황 (Total-S)성분의 함량으로 판단한다. 하지만 이들 방법은 시군농업기술센터 및 현장 진단 시 적용이 용이하지 않다. 산발생 능력평가 중 순산 발생능력실험 (Net Acid Generation, NAG pH)은 대상지역의 산성발생 가능성에 대한 예측을 정량적 계산으로 가능하다. 순산발생능력실험을 이용하여 전황함량과 NAG pH와의 상호관계를 통해 특이산성토양 판정을 제안하기 위해 화산기원의 잠재특이산성 토양과 사양질 토양을 일정비율로 혼합된 토양과 특이산성토양인 김해통과 해척통 토양에 대해 실험을 수행하였다. 전황의 함량이 0.75% 이상인 시료의 NAG pH가 2.5이며 0.75-0.50%의 중간 특이산성토양은 NAG pH 3.0으로 측정되었다. 그리고 전황 함량이 0.5-15% 약한 특이산성 토양은 NAG pH 3.8로 측정되었다. 따라서 순산발생량은 NAG pH를 이용하여 토양 내 황철석을 모두 산화시키고 pH를 측정하여 pH 3.8이하인 토양은 특이산성토양으로 구분하는 것이 타당할 것으로 판단되었다.

• 한국콘텐츠학회논문지
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• 제17권7호
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• pp.67-78
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• 2017

본 연구는 중증장애인생산품 생산시설 실태분석을 통해 중증장애인생산품 판매를 활성화하고, 생산시설 운영을 성공적으로 지원하는 방안을 제시하는데 목적이 있다. 2016년 12월 현재 지정받은 생산시설 403개 중 289개를 대상으로 조사하였다. 연구결과, 첫째, 중증장애인생산품 생산시설 289개소 중 장애인보호작업장(57.1%), 장애인복지단체(29.8%), 장애인근로사업장(13.1%) 순으로 나타났다. 근로자는 총 8,358명으로 1개 시설 평균 28.92명이고, 이중 장애인근로자는 6,119명(평균 21.17명)으로 나타났다. 근로장애인 중 중증장애인이 85.8%로 기준인 60%보다 높은 것으로 확인되었고, 근로장애인의 시급은 평균 5,235원으로 최저임금보다 낮은 수준으로 나타났다. 둘째, 지정품목은 인쇄/광고(18.6%)가 가장 많았고, 식품(14.3%), 사무/문구(12.8%)순으로 나타났다. 셋째, 총매출액은 1개소당 17.8억원이고, 매출원가는 15.7억원이며 이익은 2.1억원으로 나타났다. 또한, 지정받은 기간이 길수록 매출액이 증가하는 것으로 확인되었다. 넷째, 지정을 통하여 매출 향상, 장애인고용 향상, 장애인근로자 임금향상, 근무조건 개선에 도움이 되는 것으로 나타났다. 마지막으로, 성공적인 운영을 위해서 우선구매비율 확대(19.4%), 구매가산점 확대(17.5%), 판로지원 확대(10.2%)가 필요한 것으로 확인되었다. 이를 근거로 개선방안을 제시하였다.