• Title/Summary/Keyword: Life-stress

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A Convergence Study through Durability Analysis due to the Configuration of Automotive Lift (자동차 리프트 형상에 따른 내구성 해석을 통한 융합 연구)

  • Choi, Kye-Kwang;Cho, Jae-Ung
    • Journal of the Korea Convergence Society
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    • v.10 no.12
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    • pp.281-286
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    • 2019
  • To repair the underside of the car, a repairman has to enter under the car body. But this work can make it difficult for him to fix it and the injuries can occur. To solve these difficult problems, the developed equipment is the automotive lift. In this study, three kinds of lift models 1, 2 and 3 were designed and the material properties of the structural steel were applied. As the same load were applied under the same conditions on all models, the structural analyses were conducted. Models 2 and 3 were shown to have the structural deformation less than model 1. Also, models 2 and 3 were shown to be more stable than model 1 structurally. By utilizing the design data on a convergence research through durability analysis according to the configuration of automotive lift obtained on the basis of this result, the esthetic feeling can be shown by being converged onto the automotive repair equipment parts at actual life.

Comparison of Oribatid Mite (Acari : Oribatida) Communities among City, Suburban, and Natural Forest Ecosystems : Namsan, Kwangreung, and Mt. Jumbong

  • Lee, Joon-Ho;Park, Hong-Hyun;Kang, Bang-Hun;Jung, Chul-Eui;Choi, Seong-Sik
    • The Korean Journal of Ecology
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    • v.23 no.2
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    • pp.107-112
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    • 2000
  • Comparison of oribatid mite community structures among Namsan, Kwangreung, and Mt, Jumbong, which receive different levels of environmental stress from severe to almost none, was made in coniferous and deciduous forests, respectively. The number of species of oribatid mites was significantly lower in Namsan and Mt. Jumbong than in Kwangreung in the coniferous forest (p<0.05). In the deciduous forests, the number of species of oribatid mites was significantly lower in Namsan than in Kwangreung and Mt. Jumbong. Dominant species in 3 regions were remarkably different. Similarity of the oribatid community between Namsan and Kwangreung was much higher (ca. 2 times) than similarities between Namsan and Mt. Jumbong. and Kwangreung and Mt Jumbong. Diversity index (H$^{\prime}$) value of oribatid communities in deciduous forests in Namsan, Kwangreung and Mt. Jumbong was 2.74, 2.78, and 2.87, respectively. Diversity (H$^{\prime}$) value of oribatid communities in coniferous forests in Namsan, Kwangreung and Mt. Jumbong was 2.83, 2.62, and 2.38, respectively. Namsan and Kwangreung were characterized as O-type in both coniferous and deciduous forests On the contrary, Mt. Jumbong was characterized as MG-type in MGP-I analysis.

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Influence of Thermal Conductivity on the Thermal Behavior of Intermediate-Temperature Solid Oxide Fuel Cells

  • Aman, Nurul Ashikin Mohd Nazrul;Muchtar, Andanastuti;Rosli, Masli Irwan;Baharuddin, Nurul Akidah;Somalu, Mahendra Rao;Kalib, Noor Shieela
    • Journal of Electrochemical Science and Technology
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    • v.11 no.2
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    • pp.132-139
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    • 2020
  • Solid oxide fuel cells (SOFCs) are among one of the promising technologies for efficient and clean energy. SOFCs offer several advantages over other types of fuel cells under relatively high temperatures (600℃ to 800℃). However, the thermal behavior of SOFC stacks at high operating temperatures is a serious issue in SOFC development because it can be associated with detrimental thermal stresses on the life span of the stacks. The thermal behavior of SOFC stacks can be influenced by operating or material properties. Therefore, this work aims to investigate the effects of the thermal conductivity of each component (anode, cathode, and electrolyte) on the thermal behavior of samarium-doped ceria-based SOFCs at intermediate temperatures. Computational fluid dynamics is used to simulate SOFC operation at 600℃. The temperature distributions and gradients of a single cell at 0.7 V under different thermal conductivity values are analyzed and discussed to determine their relationship. Simulations reveal that the influence of thermal conductivity is more remarkable for the anode and electrolyte than for the cathode. Increasing the thermal conductivity of the anode by 50% results in a 23% drop in the maximum thermal gradients. The results for the electrolyte are subtle, with a ~67% reduction in thermal conductivity that only results in an 8% reduction in the maximum temperature gradient. The effect of thermal conductivity on temperature gradient is important because it can be used to predict thermal stress generation.

Preparation of Co3O4/NF Anode for Lithium-ion Batteries

  • Tian, Shiyi;Li, Botao;Zhang, Bochao;Wang, Yang;Yang, Xu;Ye, Han;Xia, Zhijie;Zheng, Guoxu
    • Journal of Electrochemical Science and Technology
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    • v.11 no.4
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    • pp.384-391
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    • 2020
  • Due to its characteristics of light weight, high energy density, good safety, long service life, no memory effect, and environmental friendliness, lithium-ion batteries (LIBs) are widely used in various portable electronic products. The capacity and performance of LIBs largely depend on the performance of electrode materials. Therefore, the development of better positive and negative materials is the focus of current research. The application of metal organic framework materials (MOFs) derivatives in energy storage has attracted much attention and research. Using MOFs as precursors, porous metal oxides and porous carbon materials with controllable structure can be obtained. In this paper, rod-shaped Co-MOF-74 was grown on Ni Foam (NF) by hydrothermal method, and then Co-MOF-74/NF precursor was heat-treated to obtain rodshaped Co3O4/NF. Ni Foam was skeleton structured, which effectively relieved. The change of internal stress changes and destroys the structural volume of the electrode material and reduces the capacity attenuation. Co3O4/NF composite material has a specific discharge capacity of up to 1858 mA h/g for the first time, and a reversible capacity of up to 902.4 mA h/g at a current density of 200 mA/g, and has excellent rate and impedance performance. The synthesis strategy reported in this article opens the way to design high-performance electrodes for energy storage and electrochemical catalysis.

Health Effects of Apartment Noise (층간소음의 건강영향)

  • Park, Young Min;Kim, Kyoung Min
    • Journal of Environmental Policy
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    • v.14 no.1
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    • pp.113-134
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    • 2015
  • In new housing demand, proportion of occupied multi-housing is 89.9% (statistics from 2013). In this way, with many generations living together, apartment noise disputes between the neighbors are continuously rising. The apartment noise problem in Korea is at a very serious level worldwide (about 88% of the population is experiencing stress due to apartment noise). On the other hand, the government has strengthened the regulations (such as the thickness of the floor and floor impact sound reduction performance, etc.) and promoted a resolution of its own for each multi-housing estates for mediating disputes on apartment noise. However, such physical regulations and passive management policies still presents a limit to the dispute mitigation of apartment noise. Also, in order to improve the quality of life in living spaces, policy on health effects of apartment noise should be provided. Therefore, we investigated a case study of the noise exposure-human body reaction to analyze the effect of noise on health. On the basis of this, the health effects according to the exposure period of apartment noise were considered.

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Autobiographical Memory in Patients with Bipolar Disorder (양극성 장애 환자의 자서전적 기억)

  • Sun, Ja-Yeun;Ha, Ra-Yeon;Lee, Su-Jin;Ryu, Vin;Ha, Kyoo-Seob;Cho, Hyun-Sang
    • Korean Journal of Biological Psychiatry
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    • v.19 no.1
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    • pp.53-59
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    • 2012
  • Objectives : Autobiographical memory (ABM) is a special type of episodic memory, containing events that have occurred in a personal life. Overgeneral tendency of ABM refers to the retrieval of memory with only general and categorical descriptions rather than specific events. ABM specificity in depression and posttraumatic stress disorder is a robust finding with relation to cognitive vulnerability, affect regulation, problem-solving ability. It is also implicated in bipolar disorder with frequent relapses. In this study, we investigated whether ABM specificity was related to manic or euthymic mood states in patients with bipolar disorder. Methods : Forty bipolar patients with manic and euthymic episodes and 25 healthy controls participated in this study. Prompted by 5 positively and 5 negatively valenced emotional cue words, each participant was instructed to recall positive or negative memories and describe them in detail. The One-way ANOVA was used to compare ABM scores and post-hoc analyses were done. Results : Comapred to the healthy persons, the bipolar patients reported significantly more general than specific negative memories in both manic and euthymic episodes (p = 0.003). However, there was no significant difference between manic and euthymic patients (p = 0.074). Conclusions : These results suggest that overgeneral tendency of negative ABM may be a trait abnormality in bipolar disorder. Moreover, this phenomenon might be related to underlying cognitive deficits or affect regulation irrespective of the mood state.

A Study of Fiber-Reinforced Material Models for the Mechanical Characteristics of Human Annulus Fibrosus (인체의 윤상인대의 역학적 특성 모사를 위한 섬유 강화 모델에 관한 연구)

  • Lim, Jun-Taek;Choi, Deok-Kee
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.6
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    • pp.619-628
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    • 2011
  • Human soft tissues, including muscles, ligaments, skin, and blood vessels, are an interesting subject because damage to them can be observed in everyday life. Besides the lack of available experimental data and the large deformation upon loading, the anisotropic and compressible nature of annulus fibrosus makes it more difficult to find a simple material model. A fiber-reinforced hyperelastic material model is used to determine the stress-strain curves upon uniaxial loading. The energy potential function for annulus fibrosus is composed of three different parts: matrix, fibers, and matrix-fiber interaction, which accounts for the angles between two families of fibers. In this paper, two different types of energy potential function for the matrix are considered, and are inserted into the fiber-reinforced model. The calculated results are compared with the Neo-Hookean model and experimental data, and reasonable agreement is observed overall.

A Literature Study on Irritable Bowel Syndrome (과민성(過敏性) 대장증후군(大腸症候群)에 대한 문헌적(文獻的) 고찰(考察))

  • Cho, Yoon-Sung;Jung, Jong-An;Hong, Gwang-Hae;Jeong, Kyoung-Ah
    • Herbal Formula Science
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    • v.14 no.2
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    • pp.9-20
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    • 2006
  • Objective & Methods : Irritable Bowel Syndrome is occurred frequently in daily life. Nevertheless. medical treatment of the Irritable Bowel Syndrome is almost dependent on western cure, but that cure is not effective enough. So we chose the oriental medicine textbook that were dealing with the oriental concept and the treatment of Irritable Bowel Syndrome. we got these results. Results were as follows : 1. Irritable Bowel Syndrome is characterised by recurrent or chronic abdominal pain, with distension, disturbed defecation and psychic problems without organic lesions. 2. The etiology of Irritable Bowel Syndrome include stress. disharmony of liver and spleen, the coldness of spleen and kidney and the lack of qi or yin, etc. 3. The oriental treatments of Irritable Bowel Syndrome are warming spleen and kidney, easing liver and stopping diarrhea. 4. The internal medication of Irritable Bowel Syndrome was the most used 11 times Tongsayobang(痛瀉要方) and 10 times Yijungtang(理中湯). 5. The most many used herb were Atractylodjs macrocephalae rhjzoma(白朮), Gjnseng Radix (人蔘), Cjnnamomj Cortex(肉桂), Polyporus(猪笭), etc.

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Research on Personal Information Safety Condition and Improvements in Welfare Center for the Disabled (장애인복지관 개인정보보호 실태와 개선 방안)

  • Kim, Sung-Jin;Kweon, Jae-Sook
    • The Journal of the Korea Contents Association
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    • v.10 no.11
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    • pp.262-274
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    • 2010
  • In Welfare Center for the disabled, under the Government's information acceleration plan, the computer system has been developed starting from work standardization in 2001 but it has been emphasized only on the technical and customer convenience side leaving out preparation for the side effects of them. Therefore this article will seek the necessity of personal information protection, legal basis in the Welfare Center for the disabled. Additionally after analyzing current status for the personal security of Welfare Center for the disabled, establishing an alternative plan for personal security policy's way could be addressed. Increasing education for awareness stress of personal information security, and preparing institutional protection apparatus from applying life cycle of personal information would be an alternative plan for personal information protection for Welfare Center for the disabled. Also frequent monitoring of accessing personal information from the computerized system should be achieved. It is impossible to recover damage caused by leak of personal information although post actions are progressed. From this essay, awareness of personal information protection should be newly revised for both the Social Welfare Organization and the Disabled welfare center, and also technical, institutional strategy's action should be arranged.

Lonchocarpine Increases Nrf2/ARE-Mediated Antioxidant Enzyme Expression by Modulating AMPK and MAPK Signaling in Brain Astrocytes

  • Jeong, Yeon-Hui;Park, Jin-Sun;Kim, Dong-Hyun;Kim, Hee-Sun
    • Biomolecules & Therapeutics
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    • v.24 no.6
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    • pp.581-588
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    • 2016
  • Lonchocarpine is a phenylpropanoid compound isolated from Abrus precatorius that has anti-bacterial, anti-inflammatory, antiproliferative, and antiepileptic activities. In the present study, we investigated the antioxidant effects of lonchocarpine in brain glial cells and analyzed its molecular mechanisms. We found that lonchocarpine suppressed reactive oxygen species (ROS) production and cell death in hydrogen peroxide-treated primary astrocytes. In addition, lonchocarpine increased the expression of anti-oxidant enzymes, such as heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1), and manganese superoxide dismutase (MnSOD), which are all under the control of Nrf2/antioxidant response element (ARE) signaling. Further, mechanistic studies showed that lonchocarpine increases the nuclear translocation and DNA binding of Nrf2 to ARE as well as ARE-mediated transcriptional activities. Moreover, lonchocarpine increased the phosphorylation of AMP-activated protein kinase (AMPK) and three types of mitogen-activated protein kinases (MAPKs). By treating astrocytes with each signaling pathway-specific inhibitor, AMPK, c-jun N-terminal protein kinase (JNK), and p38 MAPK were identified to be involved in lonchocarpine-induced HO-1 expression and ARE-mediated transcriptional activities. Therefore, lonchocarpine may be a potential therapeutic agent for neurode-generative diseases that are associated with oxidative stress.