• 제목/요약/키워드: Limiting factors

검색결과 434건 처리시간 0.034초

이미지 인페인팅을 활용한 레이다 이미지 노이즈 제거 (Noise Removal of Radar Image Using Image Inpainting)

  • 전동민;오상진;임채옥;신성철
    • 대한조선학회논문집
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    • 제59권2호
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    • pp.118-124
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    • 2022
  • Marine environment analysis and ship motion prediction during ship navigation are important technologies for safe and economical operation of autonomous ships. As a marine environment analysis technology, there is a method of analyzing waves by measuring the sea states through images acquired based on radar(radio detection and ranging) signal. However, in the process of deriving marine environment information from radar images, noises generated by external factors are included, limiting the interpretation of the marine environment. Therefore, image processing for noise removal is required. In this study, image inpainting by partial convolutional neural network model is proposed as a method to remove noises and reconstruct radar images.

Design Optimization of the Front Side in n-Type TOPCon Solar Cell

  • Jeong, Sungjin;Kim, Hongrae;Kim, Sungheon;Dhungel, Suresh Kumar;Kim, Youngkuk;Yi, Junsin
    • 한국전기전자재료학회논문지
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    • 제35권6호
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    • pp.616-621
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    • 2022
  • Numerical simulation is a good way to predict the conversion efficiency of solar cells without a direct experimentation and to achieve low cost and high efficiency through optimizing each step of solar cell fabrication. TOPCon industrial solar cells fabricated with n-type silicon wafers on a larger area have achieved a higher efficiency than p-type TOPCon solar cells. Electrical and optical losses of the front surface are the main factors limiting the efficiency of the solar cell. In this work, an optimization of boron-doped emitter surface and front electrodes through numerical simulation using "Griddler" is reported. Through the analysis of the results of simulation, it was confirmed that the emitter sheet resistance of 150 Ω/sq along the front electrodes having a finger width of 20 ㎛, and the number of finger lines ~130 for silicon wafer of M6 size is an optimized technology for the front emitter surface of the n-type TOPCon solar cells that can be developed.

포스트 코로나 시대 재택근무의 위험성과 개선방향 - 정신적, 신체적 사안을 중심으로 (Risk and Improvement Measures of Work from Home in the Post-COVID-19 Era - Focusing on Mental and Physical Issues)

  • 엄태수;신은택;송창근
    • 한국안전학회지
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    • 제38권3호
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    • pp.93-101
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    • 2023
  • The COVID-19 pandemic has significantly impacted how people work, resulting in a massive shift towards working from home or remotely. Work from home has played a critical role in reducing the transmission of COVID-19 by limiting in-person interactions and reducing the density of people in office buildings. It also enabled businesses and organizations to continue operating while keeping their employees safe and healthy. The COVID-19 pandemic accelerated the adoption of work from home in business and organizational sectors worldwide, and it is likely to continue as a preferred mode of work even after the pandemic is over. This shift towards working from home has not only impacted the way people work but also has significant implications for urban development, transportation, and the environment. This study intends to develop measures for addressing potential physical and mental health issues among remotely working employees. Additionally, it identifies the major influencing factors of home workers' health hazards and proposes improvement measures that can be applied to working from home, along with existing laws and prevention methods.

The Impact of Fatigue on Hazard Recognition: An Objective Pilot Study

  • Ibrahim, Abdullahi;Okpala, Ifeanyi;Nnaji, Chukwuma;Namian, Mostafa;Koh, Amanda
    • 국제학술발표논문집
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    • The 9th International Conference on Construction Engineering and Project Management
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    • pp.450-457
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    • 2022
  • The construction industry is demanding, dynamic, and complex making it difficult for workers to recognize hazards. The nature of construction tasks exposes workers to several critical risk factors, such as a high rate of exertion and fatigue. Recent studies suggest that fatigue may impact hazard recognition in the construction industry. However, most studies rely on subjective measures when assessing the relationship between physical fatigue and hazard recognition, limiting such studies' efficacy. Thus, this study examined the relationship between physical fatigue and hazard recognition using a controlled experiment. Worker fatigue levels were captured using physiological data and a subjective exertion scale. The findings confirmed that physical exertion plays a significant role in hazard recognition skills (p < 0.05). This research contributes to theory and practice by providing a process for objectively assessing the influence of physical fatigue on worker safety and providing construction professionals with some critical insight needed to improve workplace safety.

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Identifying torsional eccentricity in buildings without performing detailed structural analysis

  • Tamizharasi, G.;Murty, C.V.R.
    • Earthquakes and Structures
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    • 제23권3호
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    • pp.283-295
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    • 2022
  • Seismic design codes permit the use of Equivalent Static Analysis of buildings considering torsional eccentricity e with dynamic amplification factors on structural eccentricity and some accidental eccentricity. Estimation of e in buildings is not addressed in codes. This paper presents a simple approximate method to estimate e in RC Moment Frame and RC Structural Wall buildings, which required no detailed structural analysis. The method is validated by 3D analysis (using commercial structural analysis software) of a spectrum of building. Results show that dynamic amplification factor should be applied on torsional eccentricity when performing Response Spectrum Analysis also. Also, irregular or mixed modes of oscillation arise in torsionally unsymmetrical buildings owing to poor geometric distribution of mass and stiffness in plan, which is captured by the mass participation ratio. These irregular modes can be avoided in buildings of any plan geometry by limiting the two critical parameters (normalised torsional eccentricity e/B and Natural Period Ratio 𝜏 =T𝜃/T, where B is building lateral dimension, T𝜃 uncoupled torsional natural period and T uncoupled translational natural period). Suggestions are made for new building code provisions.

Molecular Identification and Fine Mapping of a Major Quantitative Trait Locus, OsGPq3 for Seed Low-Temperature Germinability in Rice

  • Nari Kim;Rahmatullah Jan;Jae-Ryoung Park;Saleem Asif;Kyung-Min Kim
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2022년도 추계학술대회
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    • pp.283-283
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    • 2022
  • Abiotic stresses such as high/low temperature, drought, salinity, and submergence directly or indirectly influence the physiological status and molecular mechanisms of rice which badly affect yield. Especially, the low temperature causes harmful influences in the overall process of rice growth such as uneven germination and the establishment of seedlings, which has become one of the main limiting factors affecting rice production in the world. It is of great significance to find the candidate genes controlling low-temperature tolerance during seed germination and study their functions for breeding new rice cultivars with immense low-temperature tolerance during seed germination. In this study, 120 lines of Cheongcheong/Nagdong double haploid population were used for quantitative trait locus analysis of low-temperature germinability. The results showed significant difference in germination under low different temperature conditions. In total, 4 QTLs were detected on chromosome 3, 6, and 8. A total of 41 genes were identified from all the 4 QTLs, among them, 25 genes were selected by gene function annotation and further screened through quantitative real time polymerase chain reaction. Based on gene function annotation and level of expression under low-temperature, our study suggested OsGPq3 gene as a candidate gene controlling viviparous germination, ABA and GA signaling under low-temperature. This study will provide a theoretical basis for marker-assisted breeding.

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Identification of Drought Tolerant Genotypes by Evaluating Morpho-physiological Traits in Pepper

  • Kyu Kyu Thin;Alebel Mekuriaw;Hyerim Do;Inhwa Yeam;Je Min Lee
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2022년도 추계학술대회
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    • pp.29-29
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    • 2022
  • The fast-changing climatic conditions make plants to be vulnerable to many abiotic stresses. Drought stress is one of the limiting factors that affect pepper production in water deficient regions. It affects plant growth and development by altering physiological, morphological, and metabolic processes. Breeding drought tolerant varieties is one of the mitigation strategies to overcome the ever increasing drought disaster. Hence, screening of new drought tolerant pepper genotypes is essential. The current study was aimed to identify new drought tolerant genotypes among the collection of pepper genetic resources. In total, 70 pepper genotypes were screened for drought tolerance after exposure to drought stress condition. The pepper genotypes were classified as highly tolerant, intermediate, or severely sensitive to drought stress based on the phenotypic analysis. Consequently, 13 genotypes significantly exhibited higher recovery rate after drought stress and were classified as highly tolerant. Comparative analysis of morphological and physiological parameters and expression of drought responsive genes between tolerant and susceptible pepper genotypes will be presented and discussed. The identified tolerant genotypes will be useful resources for breeding drought tolerant pepper cultivars.

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유기물 바인더를 사용한 $YBa_2Cu_3O_{7-{\delta}}$ 초전도 Coil의 제조 (Fabrication of $YBa_2Cu_3O_{7-{\delta}}$ Superconducting Coils with Polymer Binder)

  • 정해원;박승만;김재묵;김성수
    • 한국세라믹학회지
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    • 제27권3호
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    • pp.355-360
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    • 1990
  • One of the possible ways to make a flexible wire of high-Tc superconductiong ceramics is the extrusion of a mixture slurry of superconducting powder with an appropriate polymer binder. The fabrication procedure for $YBa_2Cu_3O_{7-{\delta}}$ superconducting coils with this plastic mass is described. The major factors limiting the formation of extruded wire are the binder content, powder size, and entrapped gas in the mixture slurries. The optimum content of binder for both good flexbility and strength of wire was estimated to be 30wt%. The finer the powder size is, the more homogeneous structure the extruded wire has. The vacuum degassing before extrusion was necessary to remove the entrapped gas in as-extruded wire. The formability of wire depends greatly on the wire radius and binder content. After burning out the binder and the successive sintering, the contacts between the superconducting grains could be made. The resistivity vs. temperature behavior measured in the final wire showed the transition temperature of 90K with narrow transition width. However, the critical current densities of these wires are much lower in comparison to those of conventional bulk specimens.

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간호대학생에게 적용한 노인환자 유사체험에 관한 연구 (A Study on Nursing Students' Elderly Patient Simulation Experience)

  • 오현수;정혜선
    • 한국산학기술학회논문지
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    • 제14권7호
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    • pp.3358-3367
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    • 2013
  • 본 연구는 충청북도 소재 일개 대학교 간호학과에 재학 중인 2학년 학생 88명(실험군: 47명, 대조군: 41명)을 대상으로 노인환자 유사체험의 효과를 검정하기 위해 수행되었으며 결과변수로는 노인 및 노인환자에 대한 태도와 공감 정도가 측정되었다. 연구 결과 노인환자 유사체험은 간호대학생의 노인 및 노인환자에 대한 태도에는 유의한 효과를 미치지 못하였으나 공감 수준을 향상시키는데 효과가 있는 것으로 나타났다. 또한 대상자들은 노인환자 유사체험에 대한 제한점으로 1회성의 단편적 경험, 노화에 대한 불안감 야기, 체험복장의 현실감 부족, 체험 과정 중의 사고 위험성 등을 제시하였고 이러한 제한점이 유사체험의 긍정적 효과를 약화시킬 수 있는 것으로 제기되었다. 따라서 이러한 제한점들을 고려하여 중재 프로그램을 개선하여 제공한다면 중재가 간호 대학생들의 노인환자에 대한 긍정적 태도와 공감적 이해증진으로 이어지는데 크게 기여할 것으로 판단되었다.

측두하악관절염에서 발생한 희귀한 골화현상 (UNUSUAL OSSIFICATION IN TMJ OSTEOARTHRITIS)

  • 안상헌;김종필;장헌수;박재범;안재진;신미정
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제18권2호
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    • pp.308-315
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    • 1996
  • Osteoarthritis is a noninflammatory degenerative disease affecting the articular surfaces and is accompanied by remodeling of the underlying bone. The sympotms of osteoarthritis of the temporomandibular joint are pain in the joint and muscles of mastication, limitation. Osteoarthritis is generally accepted that several factors can contribute to the trauma, aging process, internal derangement and MPDS. Radiographic features of the osteoarthritis are seen flattening of joint, sclerosis on flattened area and osteophyte or anterior lipping. In the past, osteoarthritis was considered to self-limiting disease. Currently, synovial chondromembrane is part of the process of osteoarthritis secondary to trauma. Synovial chondromatosis is an uncommon disease of cartilaginous transformation of synovial membrane with formation of loose bodies within the joint space. The pathogenesis is more an active metaplastic than a neoplastic process. The cause of synovial chondromatosis is unknown. Although trauma and inflammation have all been cited as possible factors in tis pathogenesis. The clinical sign and symptoms are unilateral swelling of the joint region, pain in the joint area and crepitus seem to be the most reliable signs and symptoms. Radiographic evidence of loose bodies may or may not be present. This is a case report of 66 year old female with synovial chondromatosis, that is advanced disease of the osteoarthrits. We treated patient with surgical excision of lose bodies, diskectomy and synovectomy. The defected articular fossa area was reconstructed with temporalis fascia flap. The result was satisfactory.

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