• Title/Summary/Keyword: Threat Factors

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Investigation of Effects of Lightning and Icing on an e-VTOL UAM Aircraft and a Proposal for Certification Guidance (e-VTOL UAM 항공기의 낙뢰 및 결빙 영향성 분석 및 인증기술에 관한 연구)

  • Kim, Yun-Gon;Jo, Hyeonseung;Jo, Jae-Hyeon;Park, Se-Woong;Myong, Rho-Shin
    • Journal of Aerospace System Engineering
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    • v.15 no.3
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    • pp.45-56
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    • 2021
  • Demand for UAM (Urban Air Mobility) aircraft is rapidly increasing in countries around the world due to the problem of traffic congestion in urban areas. Through research and development, various e-VTOL aircraft concepts are being prepared for commercialization, for which airworthiness certification is required, since it is a manned transportation mode for people to board. Factors that pose a fatal threat to the safe operation of UAM aircraft include lightning strikes that can cause damage to structures and disturb the navigation system, as well as icing that impairs flight stability. Since the current UAM aircraft-related lightning and icing certification technology development is insufficient, there is need to develop appropriate airworthiness certification guidelines. In this study, after analyzing the laws and regulations related to aircraft by the FAA and the EASA, we tried to incorporate the lightning and icing certification guidelines for the UAM aircraft. We also analyzed the effects of lightning and icing on UAM aircraft using computational simulation, and presented the basis for establishing practical guidelines for the certification of UAM aircraft to be adopted in the future.

The Definition of Frail Elderly and the Frailty Screening Assessment Tool: A Systematic Review (허약노인의 정의 및 허약 선별 평가도구에 관한 체계적 고찰)

  • Lee, Gyeong A;Park, Ji-Hyuk
    • Therapeutic Science for Rehabilitation
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    • v.10 no.3
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    • pp.43-56
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    • 2021
  • Objective : The objective of this study was to present the components of frailty by organizing the definitions of frail elderly and analyzing the tools used to screen them. Methods : This study searched for articles at involved frailty screening assessments in the elderly. Databases including CINAHL, Embase, Medline Complete, and PubMed were searched. The search terms were "assess" AND "frailty" AND "screening" AND ("frail elderly" OR "elderly"). Results : A total of 539 articles were identified by the search and 11 articles were selected. Frailty occurs due to the depressed function of multidimensional factors, and a frail elderly person is defined as one at high risk of health degeneration, functional impairment, and occurrence of disability, and having a high level of threat to life. Seven tools were selected from 11 articles. The most frequently used tool was the frailty phenotype, which was used in five articles (45.4%). The identified components of frailty were physical, activity participation, nutrition, psychological, social, overall health, and age. Conclusion : The results confirmed the definition and components of frailty. This study is expected to contribute to the future development of standardized evaluation tools for screening frail elderly individuals and intervention programs for the management of the frail elderly.

Relationship among the Expertise of University Liberal Arts Class Instructor, the Exercise Flow and Persistent Participation Intention Perceived by Non-Sports Major University Students (비체육 전공 대학생이 인지한 대학교 교양 수업 지도자의 전문성과 운동몰입 및 참여지속의도간의 관계)

  • Lee, Young Jun
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.3
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    • pp.735-749
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    • 2021
  • There is true that the evaluation of non-face-to-face swimming classes currently offered by universities due to the COVID-19 outbreak is generally negative. For this reason, the quality of non-face-to-face swimming classes at universities is bound to depend on the expertise of the instructor. However, whether or not of students who lack of practices of swimming could experience exercise flow and could continuously last the swimming exercise after semester or even graduation is difficult to confirm. This is considered to be a significant threat in the future not only for swimming, but also for all liberal arts and lifestyle sports. This study aimed at 281 non-athletic college students with experience of taking both swimming classes, and the need for a study on the structural relationship between exercise flow and participation intention by university swimming class leaders' expertise in non-sports majoring college students. And the results were empirically analyzed. The research results derived in this process are summarized as follows. First, the effect of swimming class leader's expertise (personality, lecture skills, student management, practical skills, basic knowledge) perceived by non-athletic college students on exercise flow (cognitive flow, behavior flow) affects cognitive flow. As a factor influencing, it was found that lecture skills had a statistically positive (+) effect, and as factors influencing behavioral commitment, the positive (+) effect was statistically significant in personality, lecture skills, student management, and basic knowledge. Second, as for the effect of exercise commitment (cognitive commitment, behavior commitment) perceived by non-athletic college students on continuous participation intention, the behavioral commitment factor was found to have a statistically positive (+) effect.

Comparison of Risk and Safety Perceptions of Industrial Hygienist (산업위생 분야 종사자들의 사회 안전의식변화에 관한 조사)

  • Lim, Dae Sung;Lee, Seung kil
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.30 no.4
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    • pp.331-341
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    • 2020
  • Objectives: This study was conducted to evaluate perceptions of safety and risk among Korean industrial hygienists and the change between before and after the Sewol Ferry Disaster in 2014. Two surveys with questionnaires composed of 51 questions were completed by attendees of the Korea Industrial Hygiene Association(KIHA) conference. Methods: One was conducted at the 2013 KIHA Fall Conference(N=181) and the other was from the 2014 KIHA Summer Conference(N=123). Between these two surveys was the Sewol Ferry Disaster on April 14, 2014, which was believed to seriously affect safety and risk perceptions in Korea. Results: It was revealed that industrial hygienists' awareness of safety rules strengthened after the Sewol Ferry Disaster(p<0.05). It was apparent that people over the age of 30 were more sensitive to social safety. There was no significant difference in the evaluation and attitude regarding governmental safety policy between the years of 2013 and 2014. The credibility of public organizations responsible for the disaster management system decreased. The self-evaluation of respondents' safety level also decreased. This trend shows mainly in the younger generation. It was evaluated that the overall social safety level decreased and the anxiety level increased. The score on social safety on a ±5 Likert scale was 0.68 in the 2013 survey and -0.33 in the 2014 survey(p<0.05). It was reported that the most serious threat factors for accident or disaster were 'building collapse > illegalities and corruption > side effects of radiation therapy >accidents in normal activity > occupational disease,' in order. They picked 'safety ignorance > hurry-up habits and culture > focusing on short-term benefit > easy-going attitude > insufficient safety education' for the causes of low social safety levels in 2013. In 2014, they were 'safety ignorance > easy-going attitude > focusing on short-term benefit > insufficient safety education > hurry-up habits and culture'. Conclusions: This study has some limitations because it was originally not designed to survey attitudes prior to the Sewol Ferry disaster in 2013. In addition, the survey targets are industrial hygienists who are familiar with occupational disease and injury.

Assessing Habitat Quality and Risk of Coastal Areasin Busan (부산 연안역의 서식지 질 및 위험도 평가)

  • Jeong, Sehwa;Sung, Kijune
    • Journal of Environmental Impact Assessment
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    • v.31 no.2
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    • pp.95-105
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    • 2022
  • Busan, where the coastal ecosystem health is deteriorating due to high development pressure and intensity of use, needs ecosystem management that considers humans and the natural environment together for sustainable use and ecosystem preservation of the coastal areas. In this study, the InVEST model was applied to assess the habitat status of the coastal land and coastal sea to manage the ecosystem based on habitats. As a result of the assessment of the coastal land, the habitat quality of Gadeok-do, Igidae, and Sinseondae, Gijang-gun are high, and Seo-gu, Jung-gu, Dong-gu, and Suyeong-gu are low. In the case of the coastal sea, the habitat risk of the Nakdong river estuary is low, and some areas of Yeongdo-gu, Saha-gu, Gangseo-gu are high. Therefore, for the sustainable use and preservation of coastal ecosystems, it is necessary to prepare ecosystem-based management measures to improve damaged habitats and reduce threats. In addition, the impact on coastal seas should be fully considered when planning coastal land development. The results of the InVEST habitat quality model in coastal land show similar tendencies to the biotope and environmental conservation value assessment map. The results of the habitat risk assessment in the coastal sea are expected to be utilized to identify habitats in the coastal sea and management of threat factors.

The Relationship between the Behavioral Characteristics of Elderly and Fatal Pedestrian Accidents (고령보행자의 행동특성과 보행사망사고의 관계)

  • Ju Seok Oh;In Seok Kim;Soon Chul Lee
    • Korean Journal of Culture and Social Issue
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    • v.16 no.1
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    • pp.1-18
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    • 2010
  • This study examines the characteristics of traffic accidents involving elderly pedestrians by analyzing relevant data vis-à-vis fatal pedestrian accidents and proposes solutions to reduce such accidents. We analyzed 3,853 cases of fatal accidents involving elderly pedestrians and 1,786 cases involving younger pedestrian (these cases reflect accidents that occurred from 2005 to 2008). The results show that accidents involving the elderly occur more frequently in rural areas than urban areas, especially in autumn; this condition applies even in situations where the elderly exhibit compensation behaviors such as walking on safer roads. We found that elderly pedestrians exhibit a defective behavior in crossing roads, especially in complicated road conditions where intersections and turning/reversing vehicles represent a menacing threat. These characteristics could be explained by the degenerated physical/mental ability of the elderly and by psychological factors such as reduced level of self-confidence.

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The Effect of Technostress on User Resistance and End-User Performance (테크노스트레스가 사용자 저항과 성과에 미치는 영향)

  • Kyoung-June Kim;Ki-Dong Lee
    • Information Systems Review
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    • v.19 no.4
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    • pp.63-85
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    • 2017
  • Recent information technology achieves remarkable progress in almost all areas where it can be applied. However, this technology also causes technostress, such as fear and pressure to individuals, due to events, such as the threat of job loss. This technostress is becoming an important factor that can affect user performance and productivity in future society where information technology will be the focus. This kind of stress should be studied considerably in academic and practical applications. The effects of technostress on individual performance remain ambiguous. Therefore, academic research is needed to prove these effects. This study aimed to clarify the direct and indirect effects of technostress on information technology end-users. We developed a research model that integrates innovation resistance and technostress theory through previous studies and analyzed the questionnaire of 317 people. The PLS structural equation model and the study results of Baron and Kenny (1986) indicated that rapid change, connectivity, reliability, and complexity are crucial factors affecting the technostress of information technology. Technostress was analyzed indirectly only through innovation resistance, which affected the performance of end-users. This study will provide new implications for the relationship between technostress and performance or productivity in the IS field.

Analysis of Sustainable Management Factors in County Parks Based on the Sustainability Evaluation Framework of Korea Nature Parks - Focus on the 11 County Parks in Gyeongsangnam-do - (자연공원 지속가능성평가에 기반한 군립공원 지속가능성 영향요인 분석 - 경남권역 11개소 군립공원을 대상으로 -)

  • Hong, Sukhwan;Ahn, Rosa;Tian, Wanting;Heo, Hagyoung;Pak, Junhou
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.3
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    • pp.12-21
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    • 2020
  • This study aims to implement the Sustainability Evaluation Framework of Korea Natural Parks to county parks in Gyeongsangnam-do, and to review the performance status of management effectiveness evaluation (MEE) and identify factors that influence the improvement of management effectiveness in protected areas. County park officers evaluated current management using this framework that was developed based on the MEE framework designed by the Korean Ministry of Environment. Among the principal values of county parks, 'natural and ecological' is indicated as the most important, followed by 'cultural and historic value' and 'leisure and recreation'. Natural disasters and climate change, visitor impact-inappropriate visitor behavior are indicated as current threats, and three county parks administrators viewed that there was no particular threat to their park. According to MEE results, the most effective management fields were 'State of cultural and historic value', 'State of leisure and recreational value', 'Current state of principal value'. The comparatively weaker fields were 'Threatened species management', 'Invasive species management', 'Management monitoring and evaluation'. The effects of sustainable management on county parks were analyzed through a regression analysis, and the influence of management factors reveal 'Annual budget', will impact attaining higher management scores. This study presents the current management information about county parks and provides support for the basis for the planning of county parks in Korea, suggesting the influencing factor.

Treatment Outcomes and Prognostic Factors in Patients with Multidrug-Resistant Tuberculosis in Korean Private Hospitals (국내 민간병원에서 치료한 다제내성결핵 환자의 치료 결과 및 예후 인자)

  • Park, Jin-Kyeong;Koh, Won-Jung;Kim, Deog-Kyeom;Kim, Eun-Kyung;Kim, Yu-Il;Kim, Hee-Jin;Kim, Tae-Hyung;Kim, Jae-Yeol;Park, Moo-Suk;Park, I-Nae;Park, Jae-Seuk;Lee, Ki-Man;Song, Sook-Hee;Lee, Jin-Hwa;Lee, Seung-Heon;Lee, Hyuk-Pyo;Yim, Jae-Joon;Lim, Jae-Min;JeGal, Yang-Jin;Jung, Ki-Hwan;Huh, Jin-Won;Choi, Jae-Chol;Shim, Tae-Sun
    • Tuberculosis and Respiratory Diseases
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    • v.69 no.2
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    • pp.95-102
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    • 2010
  • Background: The increasing rate of drug-resistant tuberculosis (TB) is a threat to the public health and TB control. In Korea, about 75~80% of TB patients are treated in private hospitals and the rate has been continuously increasing since 2000. Methods: On a retrospective basis, we enrolled 170 newly diagnosed with or retreated for multidrug-resistant TB (MDR-TB) in 2004 from 21 private hospitals. We extracted the following demographics and treatment history from patient medical records: initial treatment outcomes, cumulative survival rates, treatment outcomes, and prognostic factors. Results: Of the 170 patients, the majority were male (64.1%), the mean age was 44.5 years old, and mean body-mass-index was $20.2kg/m^2$. None of the patients tested positive for HIV. Eleven (6.5%) were confirmed to have extensively drug-resistant TB (XDR-TB) at treatment initiation. Treatment success rates were not different between XDR-TB (36.4%, 4/11) and non-XDR MDR-TB (51.6%, 82/159). Default rate was high, 21.8% (37/170). Far advanced disease on X-ray was a significant negative predictor of treatment success; advanced disease and low BMI were risk factors for all-cause mortality. Conclusion: In private hospitals in Korea, the proportion of XDR-TB in MDR-TB was comparable to previous data. The treatment success rate of MDR-/XDR-TB remains poor and the failure rate was quite high. Adequate TB control policies should be strengthened to prevent the further development and spread of MDR-/XDR-TB in Korea.

A Review Essay on Legal Mechanisms for Orbital Slot Allocation (정지궤도슬롯의 법적 배분기제에 관한 논고)

  • Jung, Joon-Sik;Hwang, Ho-Won
    • The Korean Journal of Air & Space Law and Policy
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    • v.29 no.1
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    • pp.199-236
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    • 2014
  • This paper analyses from the perspective of distributive justice the legal mechanisms for international allocation of orbital slots, which are of co-owned nature and thereby limited natural resources in outer space. The allocative function is delegated to the International Telecommunication Union. The Radio Regulation, amongst such other legal instruments as the Constitution and Convention, by which the ITU and contracting States thereof abides, dictates how the orbital positions are distributed. Thus, the RR is thoroughly reviewed in the essay. The mechanisms are in a broad sense categorized into two systems: 'a posteriori system' where the 'first come, first served' principle prevails; and 'a priori system' designed to foster the utilisation of the slots by those who lack space resources and are, in especial, likely to be marginalised under the former system. The argument proceeds on the premise that a posteriori system places the under-resourced States in unfavourable positions in the securement of the slots. In contrast with this notion, seven factors were instantiated for an assertion that the degradation of the distributive justice derived from the 'first come, first served' rule, which lays the foundation for the system, could be either mitigated or counterbalanced by the alleged exceptions to the rule. However, the author of this essay argues for counterevidences against the factors and thereby demonstrating that the principle still remains as an overwhelming doctrine, posing a threat to the pursuit of fair allocation. The elements he set forth are as in the following: 1) that the 'first come, first served' principle only applies to assignments capable of causing harmful interferences; 2) the interoperability of the principle with the 'rule of conformity' with the all the ITU instruments; 3) the viability of alternative registrations, as an exception of the application of the principle, on the condition of provisional and informational purposes; 4) another reference that matters in deciding the priority: the types of services in the TFA; 5) the Rule of Procedure H40 proclaiming a ban on taking advantage of coming first to the Register; 6) the technical factors and equity-oriented norms under international and municipal laws along with; 7) the changes of 'basic characteristics' of registered assignments. The second half of this essay illustrates by examining the relevant Annexes to the Regulation that the planned allocation, i.e., a priori system, bear the structured flaws that hinder the fulfillment of the original purpose of the system. The Broadcasting and Fixed Satellite Systems are the reviewed Plans in which the 'first come, first served' principle re-emerges in the end as a determining factor to grant the 'right to international recognition' to administrations including those who has not the allotted portions in the Plan.