• Title/Summary/Keyword: impact test method

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Connectivity Verification and Noise Reduction Analysis of Smart Safety Helmet for Shipyard Worker (조선소 작업자를 위한 스마트 안전모의 커넥티비티 검증 및 소음저감 분석)

  • Park, Junhyeok;Heo, Junyeoung;Lee, Sangbok;Park, Jaemun;Park, Jun-Soo;Lee, Kwangkook
    • Journal of the Institute of Convergence Signal Processing
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    • v.23 no.1
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    • pp.28-36
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    • 2022
  • Currently, the automation and intelligence of the shipbuilding industry have improved its work production capacity and cost competitiveness, but the reduction rate of safety accidents among industrial site workers is still low and the damage caused by safety accidents is very serious, so there is a need for improvement according to the workplace. This research aims to demonstrate the connectivity between smart safety helmets in the demonstration area to verify the effectiveness along with the development of smart helmets for worker protection and environmental safety in shipyards. For efficient communication between workers, impact noise of over 95dB was confirmed in the workplace, and noise reduction was required. To solve this problem, the filtering performance was compared and analyzed using the Butterworth, Chebyshev, and elliptic algorithms. The connectivity test and noise reduction method between smart helmets proposed in this study will increase the usability and safety of the field through the development of advanced smart helmets tailored to the shipbuilding workplace in the future.

Improvement Mechanism for Automatic Web Vulnerability Diagnosis (웹취약점 자동진단 개선방안)

  • Kim, Tae-Seop;Jo, In-June
    • The Journal of the Korea Contents Association
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    • v.22 no.2
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    • pp.125-134
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    • 2022
  • Due to the development of smartphone technology, as of 2020, 91.9% of people use the Internet[1] to frequently acquire information through websites and mobile apps. As the number of homepages in charge of providing information is increasing every year, the number of applications for web vulnerability diagnosis, which diagnoses the safety of homepages, is also increasing. In the existing web vulnerability check, the number of diagnostic personnel should increase in proportion to the number of homepages that need diagnosis because the diagnosticians manually test the homepages for vulnerabilities. In reality, however, there is a limit to securing a web vulnerability diagnosis manpower, and if the number of diagnosis manpower is increased, a lot of costs are incurred. To solve these problems, an automatic diagnosis tool is used to replace a part of the manual diagnosis. This paper explores a new method to expand the current automatic diagnosis range. In other words, automatic diagnosis possible items were derived by analyzing the impact of web vulnerability diagnosis items. Furthermore, automatic diagnosis identified possible items through comparative analysis of diagnosis results by performing manual and automatic diagnosis on the website in operation. In addition, it is possible to replace manual diagnosis for possible items, but not all vulnerability items, through the improvement of automatic diagnosis tools. This paper will explore some suggestions that can help improve plans to support and implement automatic diagnosis. Through this, it will be possible to contribute to the creation of a safe website operating environment by focusing on the parts that require precise diagnosis.

A Study the Activities of Working People in the Sports Club (직장인들의 생활체육 동호회 활동에 관한 연구)

  • Kim, Kyoung-Hyun
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.1
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    • pp.99-109
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    • 2019
  • The study was conducted to investigate the activities of working people in the sports club. The subject of this study was to take samples of workers who participated in the physical education system using the convenience sampling method. Out of a total of 400 questionnaires, 387 were used for research purposes, except for invalid or error questionnaires. Factor analysis and reliability tests were performed using IBM SPSS statistics Ver 21.0. Frequency analysis was conducted to explore the general characteristics of the study participants. An independent sample t-test ANOVA were conducted to verify differences among groups according to demographic characteristics, and a correlation analysis was conducted to examine the relationship between variables. Regression was performed to verify the effect of variable factors. The results of the study are as follows. First, there was no difference in wellness and job satisfaction according to gender. Second, there was no difference in wellness and job satisfaction according to sport. Third, there was a significant difference intellectual wellness according to age. In particular, 40s and 50s were higher than 60s and over. Fourth, there was a significant difference in social wellness according to activity duration. In particular, 1~2 years were higher than 3 years or more. Finally, If you look at the impact of working people's wellness lifestyle sports club activities on job satisfaction, the professional wellness lifestyle club activities showed significant influence on job satisfaction.

Numerical Analysis for Dynamic Behavioral Characteristics of Submerged Floating Tunnel according to Shore Connection Designs (지반 접속부 설계에 따른 수중터널의 동적 거동 특성에 대한 수치해석적 연구)

  • Seok-Jun, Kang;Joohyun, Park;Gye-Chun, Cho
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.25 no.1
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    • pp.27-41
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    • 2023
  • Submerged floating tunnels must be connected to the ground to connect continents. The displacement imbalance at the shore connection between the underground bored tunnel and submerged floating tunnel can cause stress concentration, accompanying a fracture at the shore connection. The elastic joint has been proposed as a method to relive the stress concentration, however, the effect of the elastic joints on the dynamic behavior should be evaluated. In this study, the submerged floating tunnel and shore connection under dynamic load conditions were simulated through numerical analysis using a numerical model verified through a small-scaled physical model test. The resonant frequency was considered as a dynamic behavioral characteristic of the tunnel under the impact load, and it was confirmed that the stiffness of the elastic joint and the resonant frequency exhibit a power function relationship. When the shore connection is designed with a soft joint, the resonant frequency of the tunnel is reduced, which not only increases the risk of resonance in the marine environment where a dynamic load of low frequency is applied, but also greatly increases the maximum velocity of tunnel when resonance occurs.

A Study on the Relationships among ICT Capability, Global Orientation and Export Marketing in Korean SMEs (중소기업의 ICT 역량, 글로벌지향성 및 수출마케팅의 관계에 대한 연구)

  • Rhee, Yang-Pok
    • Korea Trade Review
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    • v.42 no.2
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    • pp.251-276
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    • 2017
  • The utilization of Digital and Social Network has become be a key success factor in business operations as information technologies evolve rapidly. This study is to identity the relationship between ICT & digital utilization, global orientation and export marketing capability in Korean SMEs. Survey data of Korean SMEs in south regional areas was collected and analyzed for empirical hypothesis test by PLS structural equation method. The key findings are as follows. First, ICT utilization such as SNS, homepage and online portal does not impact directly on export marketing capability. It means that SMEs would not still take advantage of utilization of social network availability. Second, ICT utilization has positive influences on global market orientation and global network orientation. Finally, both global market orientation and network have significant impacts on export marketing capability. In conclusion, global orientation has full-mediation effects on relationship between ICT capability and global marketing. This study provides evidences and some practical insights that digital utilization have indirect influences on global marketing through global markets and network orientation in Korean SMEs. In information technology era, ICT utilization will play an important role in the process of SMEs' internationalization. Therefore, for sustainable growth and survival SMEs should manage and intensify ICT capability more strategically as one of core competence. The value of ICT capability in SMEs would be depended on their strategic perspectives toward digitalization. Additional empirical research about digital capability based on larger sample will be needed.

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A Study of the Effectiveness of Habitat for Humanity Korea's Disaster Risk Reduction Interventions: Focusing on the Mental Health of Residents of a Perennially Flooded Area in Southern Bangladesh (한국 해비타트의 재난위기경감 개입 효과성 연구: 방글라데시 남부 상습 침수지역 거주민의 정신건강 실태를 중심으로)

  • Suyeon Lee;Eunseok Seo;Goosoon Kwon
    • Journal of the Society of Disaster Information
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    • v.19 no.4
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    • pp.788-805
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    • 2023
  • Purpose: This study aimed to verify the impact of Habitat for Humanity Korea's disaster risk reduction intervention on the mental health and satisfaction with life among residents of southern Bangladesh who had constantly suffered from disaster stress due to perennial flooding. Method: The target group was 138 residents who were pre-surveyed in August 2020 and post-surveyed in November 2021. The interventions consisted of individual incremental housing, public facilities for evacuation, and disaster response training for capacity development. The data were analysed using paired sample t-tests for pre-post changes and one-way analysis of variance to identify differences between treatment groups. Result: The results showed significant improvements in residents' depression, anxiety, somatisation and satisfaction with life after the intervention, with significant differences in mental health levels between the intervention treatments. Specifically, relatively higher disaster mitigation effects were found for individual infrastructure improvements and employment facilities compared to disaster response drills. Conclusion: These results demonstrate the positive role of Habitat for Humanity Korea's disaster risk reduction interventions on the mental health recovery of disaster victims and suggest practical approaches that can be applied in disaster risk areas.

The impact of conversion and sanctification-centered educational programs on youth spirituality : Focusing on Camp 'A' (회심 및 성화 중심의 교육 프로그램이 청소년의 영성에 미치는 영향 : A캠프를 중심으로)

  • Minho Kim
    • Journal of Christian Education in Korea
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    • v.76
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    • pp.237-258
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    • 2023
  • Purpose of Research: This study examines how an intensive Christian program focused on conversion and sanctification impacts youth spirituality. While previous research was qualitative, looking at program design and family-church ties, this research provides a needed quantitative analysis of the program's effect on youths' spiritual development. Research content and method: The research, centering on 'A' Camp's focus on conversion and sanctification, used a pre-post test model with Lee and Kim's metrics to gauge youth spirituality. Conducted in a 2023 summer camp, assessments on days one and three yielded 109 valid questionnaires, analyzed via paired t-tests. As a result of the analysis, relationship with God t=-9.65, traditional faith t=-6.22, influence of spirituality t=-6.35, religious activity t=-8.32, experience of transcendent power t=-8.67, living righteously t=-8.04 It was statistically significant in all areas. Conclusion and Recommendation: The study confirmed that programs emphasizing conversion and sanctification markedly improve youth spirituality, notably enhancing experiences of God and righteous living via the Holy Spirit. These findings are pivotal for guiding future youth education programs, especially those conducted in camp settings.

The Analysis of the Fish Assemblage Characteristics by Wetland Type (River and lake) of National Wetland Classification System of Wetlands in Gyeongsangnam-do (국가습지유형분류체계의 습지 유형 (하천형과 호수형)에 따른 경남지역 습지의 어류군집 특성 분석)

  • Kim, Jeong-Hui;Yoon, Ju-Duk;Im, Ran-Young;Kim, Gu-Yeon;Jo, Hyunbin
    • Korean Journal of Ecology and Environment
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    • v.51 no.2
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    • pp.149-159
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    • 2018
  • Twenty-nine wetlands (20 river type and 9 lake type wetlands) in Gyeongsangnam-do were investigated to understand the characteristics of fish assemblages by the wetland type and to suggest management strategies. As a result, $10.3{\pm}4.8$ species were collected from river type wetlands on average (${\pm}SD$) and $9.1{\pm}4.1$ species from lake type wetlands. Thus, there was no significant difference in the number of species between them (Mann-Whitney U test, P>0.05). However, the species that constitute the fish assemblage showed statistically significant differences between the two wetland types (PERMANOVA, Pseudo-F=2.9555, P=0.007). Furthermore, the species that contribute the most to each type of fish assemblage were Zacco koreanus (river type, 28.51%) and Lepomis macrochirus (lake type, 23.21%), respectively (SIMPER). The results of the NMDS analysis using the fish assemblage by place classified the species into three groups (river type, lake type, and others). The current wetland management is only focused on endangered species, but this study shows a difference in fish assemblage by wetland type. Therefore, a management system based information on endemic species, exotic species and major contribution species should be provided. Furthermore, the classification of some types of wetlands based on the present topography was found to be ambiguous, and wetland classification using living creatures can be used as a complementary method. This study has limitations because only two types of wetlands were analyzed. Therefore, a detailed management method that can represent every type of wetland should be prepared through the research of all types of wetlands in the future.

Mild Impairments in Cognitive Function in the Elderly with Restless Legs Syndrome (노인 하지불안증후군에서의 인지기능 저하)

  • Kim, Eun Soo;Yoon, In-Young;Kweon, Kukju;Park, Hye Youn;Lee, Chung Suk;Han, Eun Kyoung;Kim, Ki Woong
    • Sleep Medicine and Psychophysiology
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    • v.20 no.1
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    • pp.15-21
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    • 2013
  • Objectives: Cognitive impairment in restless legs syndrome (RLS) patients can be affected by sleep deprivation, anxiety and depression, which are common in RLS. The objective of this study is to investigate relationship between cognitive impairment and RLS in the non-medicated Korean elderly with controlling for psychiatric conditions. Method: The study sample for this study comprised 25 non-medicated Korean elderly RLS patients and 50 age-, sex-, and education- matched controls. All subjects were evaluated with comprehensive cognitive function assessment tools- including the Korean version of Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K), severe cognitive impairment rating scale (SCIRS), frontal assessment battery (FAB), and clock drawing test (CLOX). Sleep quality and depression were also assessed with Pittsburgh sleep quality index (PSQI) and geriatric depression scale (GDS). Results: PSQI and GDS score showed no difference between RLS and control group. There was no significant difference between two groups in nearly all the cognitive function except in constructional recognition test, in which subjects with RLS showed lower performance than control group (t=-2.384, p=0.02). Subjects with depression ($GDS{\geq}10$) showed significant cognitive impairment compared to control in verbal fluency, Korean version of Mini Mental Status Examination in the CERAD-K (MMSE-KC), word list memory, trail making test, and frontal assessment battery (FAB). In contrast, no difference was observed between subjects who have low sleep quality (PSQI>5) and control group. Conclusions: At the exclusion of the impact of insomnia and depression, cognitive function was found to be relatively preserved in RLS patients compared to control. Impairment of visual recognition in RLS patients can be explained in terms of dopaminergic dysfunction in RLS.

Repeatability and Reproducibility in Effective Porosity Measurements of Rock Samples (암석시험편 유효공극률 측정의 반복성과 재현성)

  • Lee, Tae Jong;Lee, Sang Kyu
    • Geophysics and Geophysical Exploration
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    • v.15 no.4
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    • pp.209-218
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    • 2012
  • Repeatability and reproducibility in solid weight and effective porosity measurements have been discussed using 8 core samples with different diameters, lengths, rock types, and effective porosities. Further, the effect of temperature on the effective porosity measurement has been discussed as well. Effective porosity of each sample has been measured 7 times with vacuum saturation method with vacuum pressure of 1 torr and vacuum time of 80 minutes. Firstly, effective porosity of each sample is measured one by one, so that it can provide a reference value. Then for reproducibility check, effective porosity measurements with vacuum saturation of 2, 4, and 8 samples simultaneously have been performed. And finally, repeated measurements for 3 times for each sample are made for repeatability check. Average deviation from the reference set in solid weight showed 0.00 $g/cm^3$, which means perfect repeatability and reproducibility. For effective porosity, average deviations are less than 0.07% and 0.05% in repeatability and reproducibility test sets, respectively, which are in good agreement too. Most of porosities measured in reproducibility test lies within the deviation range in repeatability test sets. Thus, simultaneous vacuum saturation of several samples has little impact on the effective porosity measurement when high vacuum pressure of 1 torr is used. Air temperature can cause errors on submerged weight read and even effective porosity, because it is closely related to the temperature, density, and buoyancy of water. Consequently, for accurate measurement of effective porosity in a laboratory, efforts for maintaining air or water temperature constant during the experiment, or a temperature correction from other information are needed.