• 제목/요약/키워드: size concerns

검색결과 251건 처리시간 0.034초

분사형 소비자 제품 중 나노 물질의 흡입 노출 평가 방법 (Methodologies for Inhalation Exposure Assessment of Engineered Nanomaterial-containing Consumer Spray Products)

  • 박지훈;박미진;윤충식
    • 한국환경보건학회지
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    • 제45권5호
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    • pp.405-425
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    • 2019
  • Objective: This study aimed to review the methodologies for evaluation of consumer spray products containing engineered nanomaterials (ENM), particularly focusing on inhalation exposure. Method: Literature on the evaluation methods for aerosolized ENM exposure from consumer spray products were collected through academic web searching. Common methodologies used in the literature, including research reports and academic articles, were also introduced. Results: The number of ENM-containing products have shown a considerable increase over recent years, from 54 in 2005 to 1,827 in 2018. Currently there is still discussion over the existing regulations with regard to product safety. Analysis of both ENM suspensions in the products and their aerosols is important for risk assessment. Comparison between the phases suggests how the size and concentration of particles change during the spray process. To analyze the ENM suspensions, dynamic light scattering, electron microscopy techniques, and inductively coupled plasma with mass spectrometry were used. In the aerosol monitoring, direct-reading instruments have been used to monitor the aerosols and conventional active sampling is used together to supplement the lack of real-time monitoring. There are also some models for estimating inhalation exposure. These models may be used to estimate mass exposure to nanomaterials contained in consumer products. Conclusion: Although there is no standardized method to evaluate ENM exposure from consumer products, many concerns about ENM have emerged. Every potential measure to reduce exposure to ENM from spray product use should be implemented through a precautionary recognition.

DEMATEL 기법을 활용한 프로젝트 관리 성공을 저해하는 장애요인 간의 영향 관계 분석 (Analyzing the Influence Relationship between Barriers to Success of Project Management Using DEMATEL Method)

  • 이아연;장미경
    • 산업경영시스템학회지
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    • 제44권3호
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    • pp.214-229
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    • 2021
  • There is an increasing need for complex and large projects to be carried out quickly. As the duration, size, and cost of the project increase, concerns about project failure are also rising. Finding factors that hinder the performance of an effective project and eliminating them in advance or controlling and managing them more effectively can be a more direct way to secure the success of the project. Previous studies have identified compositional dimensions that are classified according to attributes, covering the various obstacles that affect the success of the project through existing literature. It is a follow-up to previous research. Using DEMATEL techniques, we would like to propose to explore the appropriate measures that an entity and organization can take by identifying the causality between factors through cross-impact analysis of project disabilities and even presenting factors that may arise when they are identified. As a result of the analysis, according to the indicators to evaluate the importance, 8 factors were found to be relatively important factors, excluding the factors that Failure of project feasibility analysis and Technical environment change. In addition, 5 factors were found to be causative factors; Technical environment change, Unclarity project plan, Strategic consistency error, Inaccuracy of requirement definition, and Failure of project feasibility analysis. In contrast, the remaining 5 factors were found to be the result factors; Lack of benefits realization, Negative attitude of top management, Stakeholder conflict, Difficulty of process management, and Disturbance of communication.

A Lightweight and Privacy-Preserving Answer Collection Scheme for Mobile Crowdsourcing

  • Dai, Yingling;Weng, Jian;Yang, Anjia;Yu, Shui;Deng, Robert H.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제15권8호
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    • pp.2827-2848
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    • 2021
  • Mobile Crowdsourcing (MCS) has become an emerging paradigm evolved from crowdsourcing by employing advanced features of mobile devices such as smartphones to perform more complicated, especially spatial tasks. One of the key procedures in MCS is to collect answers from mobile users (workers), which may face several security issues. First, authentication is required to ensure that answers are from authorized workers. In addition, MCS tasks are usually location-dependent, so the collected answers could disclose workers' location privacy, which may discourage workers to participate in the tasks. Finally, the overhead occurred by authentication and privacy protection should be minimized since mobile devices are resource-constrained. Considering all the above concerns, in this paper, we propose a lightweight and privacy-preserving answer collection scheme for MCS. In the proposed scheme, we achieve anonymous authentication based on traceable ring signature, which provides authentication, anonymity, as well as traceability by enabling malicious workers tracing. In order to balance user location privacy and data availability, we propose a new concept named current location privacy, which means the location of the worker cannot be disclosed to anyone until a specified time. Since the leakage of current location will seriously threaten workers' personal safety, causing such as absence or presence disclosure attacks, it is necessary to pay attention to the current location privacy of workers in MCS. We encrypt the collected answers based on timed-release encryption, ensuring the secure transmission and high availability of data, as well as preserving the current location privacy of workers. Finally, we analyze the security and performance of the proposed scheme. The experimental results show that the computation costs of a worker depend on the number of ring signature members, which indicates the flexibility for a worker to choose an appropriate size of the group under considerations of privacy and efficiency.

전자파 차폐 임부복 개발을 위한 고령 산모의 임부복 착용 실태조사 (Actual Wearing State of Aged Pregnant Women for the Development of Electromagnetic Waves Shielding Maternity Wear)

  • 김영임;이정란
    • 한국의류산업학회지
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    • 제21권5호
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    • pp.618-626
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    • 2019
  • This study conducted basic studies to develop electromagnetic wave shielding maternity wear. We investigated electromagnetic wave shielding fabrics and products as well as surveyed actual wearing states for pregnant women aged 35 to 44 and women who gave birth within the past one year. Available electromagnetic wave blocking products for pregnant women were blankets, aprons, maternity belts, and underwear. These only cover the abdomen and it was hard to find out electromagnetic waves shielding maternity wear, which can enhance functionality and complement the body shapes of pregnant women. The aged mother responded pregnancy delay was mostly attributable to late marriage, career, financial difficulty and health problems. Major health threats to babies were high stress levels during pregnancy, followed by electromagnetic waves from electronic devices. They prioritized physical activity, design, functionality and safety when wearing maternity wear. When purchasing maternity wear, they emphasized design, price, materials and size. The most preferred clothing was one-piece dress; consequently, only 11.1% of them were satisfied with the quality of maternity wear with complaints mostly about design and price. A total of 63% of respondents tried to protect themselves from electromagnetic waves. Most aged mothers showed a positive intention on purchasing electromagnetic waves blocking maternity wear for babies with concerns dealing with safety of materials, prices, ease of laundry, and body complementing design.

발전기의 전자기장 분포 특성에 따른 작업자 노출공간 분석 (Analysis of Worker Exposure Space according to Distribution of Electromagnetic Field of Generator)

  • 성민영;김두현;김승태
    • 한국안전학회지
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    • 제36권4호
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    • pp.20-28
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    • 2021
  • With an increase in the commercialization of electricity, and the development of advanced and large electric devices and various wireless radio wave services, concerns over the effects of electromagnetic fields on human health have increased. Accordingly, the World Health Organization encouraged the development of international standards by establishing the 'International Electromagnetic Fields Project' in 1996 based on studies on the harmful effects of electromagnetic fields on the human body. Moreover, the National Institute of Environmental Health Sciences (NIEHS) classified electromagnetic fields as possible carcinogens under Group 2B category, even though they have been found to have a weak correlation with those effects on human health. Mid-to-large-sized electric facilities used at industrial sites mostly adopt a commercial frequency of 60 Hz, and workers handling these facilities are exposed to such extremely low frequency (ELF) fields for a long time. A previous study suggested that exposure to ELF electromagnetic fields with frequency ranges from 0 to 300 Hz, even for a short time, at densities higher than 100 μT may have harmful effects on human body as it affects the activation of nerve cells in the central nervous system by inducing an electric field and current and stimulating muscles and the nervous system in the body. Such studies, however, focused on home appliances used by ordinary people, and research on facilities utilizing high-capacity current and operated by workers at industrial sites is lacking. Therefore, in this study, a 3000 kilowatt generator, which is a high-capacity electric facility employed at industrial sites, was investigated, and the size of the magnetic fields generated during its no-load and high-load operations per distance to produce a map was measured to reveal spots deemed hazardous according to domestic and international exposure standards. The findings of this study is expected to alleviate workers' anxiety about the harmful effects of magnetic fields on their body and to minimize the level of exposure during operations.

지방분권과 균형발전을 위한 행정구역 개편 -일본 사례를 통한 시사점을 중심으로- (Reorganization of Local Administrative Districts for Decentralization and Balanced Regional Development: Implications from the Japanese case)

  • 강정구;김현수;마강래
    • 지역연구
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    • 제38권1호
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    • pp.33-44
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    • 2022
  • 최근 지방의 인구감소 위기가 점차 심화하면서 지방분권을 확대해야 한다는 목소리가 점차 커지고 있다. 현 정부에서도 '재정분권 추진', '「지방이양일괄법」제정' 등을 통해 분권을 위한 여러 노력을 기울이고 있지만 분권이 오히려 국토 불균형을 악화시킬 수 있다는 우려를 담은 연구도 나오고 있다. 이들 연구는 분권에 앞서 지역 간 격차를 줄이는 선제 조치가 필요함을 강조한다. 지역의 위기를 극복하기 위한 분권 논의와 관련하여 본 연구에서는 우리나라보다 먼저 지방분권을 추진했던 일본의 사례를 살펴보았다. 일본의 지방분권은 국가적 경제위기 속에서 중앙정부의 재정부담을 줄일 목적으로 추진되었다는 점에서 우리나라와는 맥락이 다르다. 하지만 분권 추진 과정에서 행정구역 개편을 통한 공간구조의 재편을 매우 중요하게 고려하였다는 점은 우리가 주목할 만하다. 본 연구는 일본의 분권추진 과정에서 나타난 행정구역 개편 노력을 비판적으로 고찰하고, 일본 사례가 우리나라 분권 논의에 주는 시사점을 도출하였다.

Environmental and Socioeconomic Determinants of Grain Virtual Water Trade: An Empirical Analysis using Decomposition and Decoupling Model

  • Golden Odey;Bashir Adelodun;Seulgi Lee;Kyung Sook Choi
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2023년도 학술발표회
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    • pp.394-394
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    • 2023
  • The world's sustainable growth is being severely hampered by the inefficient use of water resources. Despite the widely acknowledged importance of trade in global and regional water and food security, societal reliance on local production as well as international trade remains inadequately assessed. Therefore, using South Korea as a case study, this study fills in this research gap by applying the virtual water concept, the logarithmic mean divisia index (LMDI) method, and the Tapio decoupling model. The virtual water concept was used to estimate South Korea's net virtual water trade for major grain crops from 1992 to 2017. Then, the LMDI method was utilized to assess the driving factors causing changes in net virtual water trade. Lastly, the Tapio decoupling model was used to investigate the decoupling relationships between economic growth and the driving factors of net virtual water trade. Results showed that South Korea remains a net importer of virtual water flows with respect to grain crops, with an average import of 16,559.24 million m3 over the study period. In addition, the change in net virtual water trade could be attributed to water intensity effect, product structure effect, economic effect, and population effect. However, water intensity and economic effects were the major decisive factors for decrease and increase in net virtual water trade respectively, while the population and product structure effects had minor positive influences on the net virtual water trade. Furthermore, water intensity and economic growth showed a strong decoupling in most periods, while the decoupling state between product structure and economic growth was observed as expansive negative decoupling. Likewise, population size and economic growth showed a weak decoupling in most periods. The results reveal South Korea's status as it concerns the virtual water trade of grain crops, thus providing valuable insights into the sustainability of trade activities for the management of local water resources.

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Comparative Efficacy of Various Formalin Fixatives for Molecular Diagnosis in Pathological Tissues

  • Woohyun Jee;Moonhwan Bae;Hyejin Yoon;Inyoung Kang;Myoungjoo Koo;Jaewang Lee;Jin Hyun Jun
    • 대한의생명과학회지
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    • 제28권4호
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    • pp.298-306
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    • 2022
  • Pathological tissue fixation using formalin has been widely used for histological samples in many hospitals and institutions. In general, formalin fixatives were either manufactured in laboratories or purchased commercially because of the risks and environmental concerns of handling organic compounds. In this study, the efficacy of three kinds of commercially purchased and one laboratory-made formalin fixative was compared in the PCR-based molecular diagnosis using the extracted DNA from formalin-fixed paraffin-embedded (FFPE) tissues. The quality of extracted DNA from FFPE tonsil tissues with four kinds of formalin solutions was evaluated, and PCR for beta-globin gene and microsatellite instabilities (MSI) tests for pentaplex panel markers were performed using the extracted DNA. There was no difference in PCR and MSI tests as molecular diagnoses regardless of the types of formalin used in this study. However, the total amount and average length of double-stranded DNA extracted from FFPE tonsil tissue showed significant differences according to the type of formalin fixative. Optimized formalin fixatives and methods for DNA extraction might be sophisticated to extract good quality DNA from the small size of specific tissue samples. Further studies are needed to select the most effective formalin fixative for histology and molecular pathology using human FFPE tissues.

YOLO 기반 실종자 수색 AI 응용 시스템 구현 (Implementation of YOLO based Missing Person Search Al Application System)

  • 김하연;김종훈;정세훈;심춘보
    • 스마트미디어저널
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    • 제12권9호
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    • pp.159-170
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    • 2023
  • 실종자 수색은 많은 시간과 인력이 필요하다. 그 해결책의 일환으로 YOLO 기반 모델을 활용하여 실종자 수색 AI 시스템을 구현하였다. 객 객체 탐지 모델을 훈련하기 위해 AI-Hub에서 드론 이동체 인지 영상(도로 고정)을 수집하고 모델을 학습하였다. 또한, 훈련 데이터 세트와 상이한 환경에서의 성능을 평가하기 위해 산악 환경 데이터 세트를 추가 수집하였다. 실종자 수색 AI 시스템의 최적화를 위해 모델 크기 및 하이퍼파라미터에 따른 성능평가, 과대적합 우려에 대한 추가 성능평가를 시행하였다. 성능평가 결과 YOLOv5-L 모델이 우수한 성능을 보이는 것을 확인할 수 있었으며 데이터 증강 기법을 적용함에 따라 모델의 성능이 보다 향상되었다. 이후 웹 서비스에는 데이터 증강 기법을 적용한 YOLOv5-L 모델을 적용하여 실종자 수색의 효율성을 높였다.

Deep-learning performance in identifying and classifying dental implant systems from dental imaging: a systematic review and meta-analysis

  • Akhilanand Chaurasia;Arunkumar Namachivayam;Revan Birke Koca-Unsal;Jae-Hong Lee
    • Journal of Periodontal and Implant Science
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    • 제54권1호
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    • pp.3-12
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    • 2024
  • Deep learning (DL) offers promising performance in computer vision tasks and is highly suitable for dental image recognition and analysis. We evaluated the accuracy of DL algorithms in identifying and classifying dental implant systems (DISs) using dental imaging. In this systematic review and meta-analysis, we explored the MEDLINE/PubMed, Scopus, Embase, and Google Scholar databases and identified studies published between January 2011 and March 2022. Studies conducted on DL approaches for DIS identification or classification were included, and the accuracy of the DL models was evaluated using panoramic and periapical radiographic images. The quality of the selected studies was assessed using QUADAS-2. This review was registered with PROSPERO (CRDCRD42022309624). From 1,293 identified records, 9 studies were included in this systematic review and meta-analysis. The DL-based implant classification accuracy was no less than 70.75% (95% confidence interval [CI], 65.6%-75.9%) and no higher than 98.19 (95% CI, 97.8%-98.5%). The weighted accuracy was calculated, and the pooled sample size was 46,645, with an overall accuracy of 92.16% (95% CI, 90.8%-93.5%). The risk of bias and applicability concerns were judged as high for most studies, mainly regarding data selection and reference standards. DL models showed high accuracy in identifying and classifying DISs using panoramic and periapical radiographic images. Therefore, DL models are promising prospects for use as decision aids and decision-making tools; however, there are limitations with respect to their application in actual clinical practice.