• Title/Summary/Keyword: Instability Condition

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Stability analysis of an unsaturated expansive soil slope subjected to rainfall infiltration

  • Qi, Shunchao;Vanapalli, Sai K.;Yang, Xing-guo;Zhou, Jia-wen;Lu, Gong-da
    • Geomechanics and Engineering
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    • v.19 no.1
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    • pp.1-9
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    • 2019
  • Shallow failures occur frequently in both engineered and natural slopes in expansive soils. Rainfall infiltration is the most predominant triggering factor that contributes to slope failures in both expansive soils and clayey soils. However, slope failures in expansive soils have some distinct characteristics in comparison to slopes in conventional clayey soils. They typically undergo shallow failures with gentle sliding retrogression characteristics. The shallow sliding mass near the slope surface is typically in a state of unsaturated condition and will exhibit significant volume changes with increasing water content during rainfall periods. Many other properties or characteristics change such as the shear strength, matric suction including stress distribution change with respect to depth and time. All these parameters have a significant contribution to the expansive soil slopes instability and are difficult to take into consideration in slope stability analysis using traditional slope stability analysis methods based on principles of saturated soil mechanics. In this paper, commercial software VADOSE/W that can account for climatic factors is used to predict variation of matric suction with respect to time for an expansive soil cut slope in China, which is reported in the literature. The variation of factor of safety with respect to time for this slope is computed using SLOPE/W by taking account of shear strength reduction associated with loss of matric suction extending state-of-the art understanding of the mechanics of unsaturated soils.

Estimation of Job Stress Relieve Coefficient through Recognizing Health Effects of Workers and Death Rate per 10,000 workers - A manufacturing worker - (근로자의 건강영향인지와 사망만인율을 통한 직무스트레스 해소계수 산정 - 제조업 현장근로자를 중심으로 -)

  • Han, Man Hyeong;Chon, Young Woo;Lee, Ik Mo;Hwang, Yong Woo
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.29 no.1
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    • pp.69-81
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    • 2019
  • Objective: The purpose of this study was to find out what kind of change in death rate when job stress is solved by calculating job stress relieve coefficient. Methods: This study used the data of the fourth working condition survey. Regression analysis was used to determine the relationship between health effects recognition and Death rate per 10,000 workers. After that the recognizing and non - recognizing groups were categorized by health effects recognition, and the differences between the two groups were confirmed by cross tabulation analysis. Results: Regress analysis P-value is 0.011 and $R^2$ is 0.979. Death rate per 10,000 worker increased with the increase in the number of non - health impact recognizing group. The relieve factors were (1) work culture(2.859) (2) physical environment(2.184), (3) improper reward (1,839), (4) relationship conflict(1.646), (5) job requirement(1.613), (6) job autonomy(1.354), (7) job instability(1.334), And (8) organizational system(1.201). The higher the relieve coefficient is, the higher the probability of belonging to the non - health impact recognizing group when there is no job stress factor. Conclusions: When job stress is resolved, there is a high probability that the health impact recognition is reduced, which can lead to an increase in death rate. but according to previous studies, Job stress can cause accidents by reducing the safety behavior of accidents. The job stress management plan should simultaneously consider reducing job stress and increasing health impact recognition.

Performance Analysis of Mode Switching Scheme for Reduction of Phase Distortion in GPS Anti-jamming Equipment Based on STAP Algorithm

  • Jung, Junwoo;Yang, Gi-Jung;Park, Sungyeol;Kang, Haengik;Kwon, Seungbok;Kim, Kap Jin
    • Journal of Positioning, Navigation, and Timing
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    • v.8 no.3
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    • pp.95-105
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    • 2019
  • A method that applies space-time adaptive signal processing (STAP) algorithm based on an array antenna consisting of multiple antenna elements has been known to be effective to remove wide-band jamming signals in GPS receivers. However, the occurrence of phase distortion in navigation signals has been a problem when navigation signals, from which jamming signals are removed using STAP, are supplied to global positioning system (GPS) receivers. This paper verified the navigation performance degradation as a result of phase distortion. To mitigate this phenomenon, this paper proposes a mode switching scheme, in which a bypass mode is adopted to make the best use of the tracking performance of receivers without performing signal processing when jamming signals are not present or weak, and a STAP mode is employed when jamming signals exceed the threshold value. In this paper, the mode switching scheme is proposed for two environments: when receivers are stationary, and when receivers are moving. This paper confirmed that the performance of position error improved because phase distortion could be excluded due to STAP if the bypass mode was adopted under a condition where the jamming signal power level was below the threshold value in an environment where receivers were stationary. However, this paper also observed that the navigation failed due to the instability of tracking performance of receivers due to phase distortion that occurred at the switching time, although the number of switching could be reduced dramatically by proposing a dual threshold scheme of on- and off-thresholds that switched a mode due to the array antenna characteristics of varying gains according to the jamming signal incident direction in an environment where receivers were moving. The analysis results verified that running the STAP algorithm at all times is more efficient than the mode switching, in terms of maintaining stable navigation and ensuring position error performance, to remove jamming signals in an environment where receivers were moving.

Digital Marketing in the Condition of Wartime Posture in Ukraine

  • Dubovyk, Tetiana;Buchatska, Iryna;Diachuk, Iryna;Zerkal, Anastasiia
    • International Journal of Computer Science & Network Security
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    • v.22 no.7
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    • pp.206-212
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    • 2022
  • Strengthening global geopolitical instability in the world leads to an aggravation of international conflicts; it destabilizes the domestic political situation in countries, violates the rights and freedoms of man and citizen, and also activates economic crime. The full-scale invasion of the Russian Federation on the territory of Ukraine and the deployment of military operations in a large territory of a sovereign country have created a number of destabilizing factors in the development of digital technologies and negatively affect the state and trends of digital marketing, which allows establishing interaction with a wide audience and facilitating the search for new customers in various places. The purpose of the research lies in substantiating the theoretical and applied principles for studying the features of digital marketing in the conditions of wartime posture in Ukraine. In the course of the research, general and special methods of economic analysis have been used and applied, namely: analysis and synthesis; analogies and comparisons; generalization and systematization; graphic and tabular methods. Regarding the results of the research of digital marketing in the conditions of wartime posture in Ukraine, it has been established that the intensification of the development of digital marketing is caused by the crisis phenomena of social-economic, social-political and military nature, as well as exacerbated by the challenges of the COVID-19 pandemic. It has been proven that highly developed countries use innovative digital technologies more effectively in the field of marketing, which indicates the importance of the Multidimensional Index of Digitization (the USA - MID: 0,92-0,92; the UK - MID: 0,80-0,97; Japan - MID: 0,80-0,88; Canada - MID: 0,78-0,81; Germany - MID: 0,78-0,88; France - MID: 0,72-0,76), however, the developing countries record much lower values (Ukraine - MID: 0,22-0,48). Accordingly, the level of cybersecurity in highly developed countries is also significantly higher than in transitive countries, in particular, in the United States (GCI: 0,919-0,999); Great Britain (GCI: 0,783-0,995); Canada (GCI: 0,818-0,978) and in Ukraine (GCI: 0,501-0,661).

Diagnosing Balamuthia mandrillaris amebic meningoencephalitis in a 64-year-old woman from the Southwest of China

  • Suhua Yao;Xiaoting Chen;Lian Qian;Shizheng Sun;Chunjing Zhao;Zongkai Bai;Zhaofang Chen;Youcong Wu
    • Parasites, Hosts and Diseases
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    • v.61 no.2
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    • pp.183-193
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    • 2023
  • Balamuthia mandrillaris amebic encephalitis (BAE) can cause a fatal condition if diagnosis is delayed or effective treatment is lacking. Patients with BAE have been previously reported in 12 provinces of China, with skin lesions being the primary symptom and encephalitis developing after several years. However, a significantly lower number of cases has been reported in Southwest China. Here we report an aggressive BAE case of a 64-year-old woman farmer with a history of skin lesions on her left hand. She was admitted to our hospital due to symptoms of dizziness, headache, cough, vomiting, and gait instability. She was initially diagnosed with syphilitic meningoencephalitis and received a variety of empirical treatment that failed to improve her symptoms. Finally, she was diagnosed with BAE combined with amebic pneumonia using next-generation sequencing (NGS), qRT-PCR, sequence analysis, and imaging studies. She died approximately 3 weeks after the onset. This case highlights that the rapid development of encephalitis can be a prominent clinical manifestation of Balamuthia mandrillaris infection.

How Supernovae Ejecta Is Transported In A Galaxy: DependenceOn Hydrodynamic Schemes In Numerical Simulations

  • Shin, Eun-jin;Kim, Ji-hoon
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.48.4-48.4
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    • 2019
  • We studied the metal-distribution of isolated Milky-way mass galaxy using various hydrodynamic solvers and investigated the difference of the result between AMR and SPH codes. In particle-based codes, physical quantities like mass or metallicity defined in each particle are conserved unless being injected explicitly by the effect of the supernova, whereas in the Eulerian codes the diffusion is simply accomplished by hydro-equation. Therefore, without including explicit physics of diffusion on the SPH- codes, the metal mixing in the galaxy or CGM only can be accomplished by the direct motion of the particles, however, the standard-SPH codes depress the instability of the turbulent fluid mixing. In this work, we simulated under common initial conditions, common gas-physics like cooling-heating models, and star-formation feedback using ENZO(AMR) GIZMO and GADGET-2 codes. We additionally included a metal-diffusion algorithm on the SPH-codes, which follows the subgrid-turbulent mixing model investigated by Shen et al. (2010) and compared the effect of the metal-outflow on the halo region of the galaxy in different hydro-solvers. We also found that for the implementation of the diffusion scheme in the SPH-codes, the existence of a sufficient number of the gas-particles, which is the carrier of the metals, is necessary. So we tested a new initial condition for proper implementation of the diffusion scheme on the SPH simulations. By comparing the metal-contamination of the circumgalactic medium with different hydrodynamics models, we quantify the diffusion strength of AMR codes using diffusion parameterization of the SPH codes and also suggest the calibration solutions in the different behavior of codes in metal-outflow.

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A Study on the Grotesque Tendency in German Expressionism - Focused on Café Müller (독일 표현주의에 내재된 그로테스크 성향 연구 - 카페 뮐러(Café Müller)를 중심으로)

  • CHOI, Jung Yun
    • Trans-
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    • v.15
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    • pp.105-140
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    • 2023
  • This study aims to investigate the interrelationship between German expressionist dance and grotesque art, with a specific focus on the analysis of Pina Bausch's renowned work, <Café Müller>. German expressionist dance emerged as a response to the social instability and economic downturn that followed World War I, leading to the introduction of expressionism and grotesque aesthetics. The incorporation of grotesque expression in dance plays a critical role in boldly portraying the destruction of the human condition and its underlying causes, thereby offering insights into social contradictions and the erosion of human nature. This research thoroughly explores the intricate connection between German expressionist dance and grotesque expression, providing a comprehensive analysis of Pina Bausch's <Café Müller> to reassess the profound meaning and significance of expressionist dance. Additionally, this study delves into the inherent grotesque tendencies embedded within the work, surpassing conventional notions of visual beauty and ugliness, and strives to reinterpret the essence of grotesque expression through the nuanced movements of the dancers and the integration of auditory elements within the performance.

Stability Analysis on Unsaturated Gneiss Weathered Soil Slopes Considering Wetting Path Soil-Water Characteristic Curve (습윤경로 함수특성곡선을 고려한 불포화 편마풍화토 사면의 안정해석)

  • Park, Seong-Wan;Shin, Gil Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5C
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    • pp.191-198
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    • 2009
  • It has been reported in Korea that surface slope failures in weathered soil are mainly caused by downward infiltration due to rainfall. These failures are triggered by the deepening of the wetting band in soils accompanied by a decrease in matric suction induced by the water infiltration. So, a need exists that these trends of wetting path in gneiss weathered soils, which is commonly found in Korea, are assessed by phenomenological approach. In this paper, numerical analyses of unsaturated soil slope under rainfall conditions are presented based on the wetting path soil-water characteristic curve in the laboratory. As the field SWCC matches well with the wetting path of the laboratory SWCC from the literatures, it seems reasonable to adopt the laboratory wetting SWCC as an upper boundary condition in the assessment of unsaturated slope instability.

Isolated Bilateral Midbrain Infarction in A Healthy Female Adolescent: A Case Report

  • Dong Ho Yoo;Byunghoon Lee;Yong Beom Shin;Myung-Jun Shin;Jin A Yoon;Sang Hun Kim
    • Physical Therapy Rehabilitation Science
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    • v.12 no.3
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    • pp.207-213
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    • 2023
  • Objective: The purpose of this study was to understand the complex anatomical structure and function of the midbrain to better understand the patient's symptoms and plan effective treatment including pharmacological and rehabilitation interventions. Design: A single case study Methods: A 17-year-old girl presented with acute onset of drowsiness, gait disturbance, mutism, and ptosis. Physical examination revealed postural instability, rigidity of all limbs, and limitations in extraocular movement. The brain MRI revealed an isolated acute infarction in the bilateral midbrain. Considering the location of the infarction, the presenting symptoms were the result of an impairment of the dopaminergic pathway in addition to lesions in the nuclei of the oculomotor nerve. Levodopa/carbidopa was prescribed. And the intensive and comprehensive rehabilitation program was done. Results: As a result of the study, through comprehensive intervention, which encompassed assessments such as the manual muscle test, Korean Modified Barthel Index score, and Trail-making test, significant enhancements in the patient's condition were observed. These findings provide evidence supporting the effectiveness of the intervention in promoting the patient's physical functioning and overall well-being. Conclusions: The results of this case highlight the significance of comprehending the intricate anatomical structure and functional aspects of the midbrain, which led us to approach appropriate pharmacological and rehabilitation interventions. Through active communication among the medical team, we were able to establish a therapeutic plan, which demonstrated that effective treatment can be achieved.

Peroneal Muscle and Biceps Femoris Muscle Activation During Eversion With and Without Plantarflexion in Sitting and Side-lying Postures

  • Do-eun Lee;Jun-hee Kim;Seung-yoon Han;Oh-yun Kwon
    • Physical Therapy Korea
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    • v.31 no.1
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    • pp.18-28
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    • 2024
  • Background: Lateral instability of the ankle is one of the most common causes of musculoskeletal ankle injuries. The peroneus longus (PL) and peroneus brevis (PB) contribute to ankle stability. In early rehabilitation, isometric exercises have been selected for improvement of ankle stability. To effectively train the peroneal muscles during eversion, it is important to consider ankle and body posture. Objects: This study aimed to compare activation of the PL, PB, and biceps femoris (BF) muscles during eversion in different ankle postures (neutral [N], plantarflexed [PF]) and body postures (sitting and side-lying). Methods: Thirty healthy individuals with no history of lateral ankle sprains within the last 6 months were included in the study. Maximal isometric strength of eversion and muscle activation were measured simultaneously. Muscle activation at submaximal eversion was divided by the highest value obtained from maximal isometric eversion among the four postures (percent maximal voluntary isometric contraction [%MVIC]). To examine the differences in muscle activation depending on posture, a 2 × 2 repeated measures analysis of variance (ANOVA) was conducted. Results: There were significant interaction effects of ankle and body postures on PL muscle activation and evertor strength (p < 0.05). The PL muscle activation showed a significantly greater difference in the side-lying and PF conditions than in the sitting and N conditions (p < 0.05). Evertor strength was greater in the N compared to the PF condition regardless of body posture (p < 0.05). In the case of PB and BF muscle activation, only the main effects of ankle and body posture were observed (p < 0.05). Conclusion: Among the four postures, the side-lying-PF posture produced the highest muscle activation. The side-lying-PF posture may be preferred for effective peroneal muscle exercises, even when considering the BF muscle.