• Title/Summary/Keyword: damage process

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Characteristics and Trends of Spatiotemporal Distribution of Frost Occurrence in South Korea for 21 Years (21년간 한국의 서리발생 시·공간 분포 특성과 경향)

  • Jo, Eunsu;Kim, Hae-Min;Shin, Ju-Young;Kim, Kyu Rang;Lee, Yong Hee;Jee, Joonbum
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.24 no.2
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    • pp.83-94
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    • 2022
  • In order to actively prepare to frost damage that occurs in the process of growing crops, the spatial and temporal distribution of frost occurrence in South Korea was derived using frost observation data from 20 regions over the past 21 years (2000~2020). The main products are the number of frost days, first frost day, and last frost day by region. And the climatic trends of these results were identified by performing the Mann-Kendall trend test and Sen's slope estimator. In South Korea, a lot of frost occurs in the inland area to the west of the Taebaek and Sobaek Mountains. Relatively closer to the coastal area, the number of frost days is small, the first frost day is slow, and the last frost day is early. The east coast region has fewer frost days, the first frost day is later, and the last frost day is earlier than the west coast region. The southern sea, the southeastern sea region, and the island region rarely experience frost. As a result of the annual time series trend analysis, although South Korea is a country where climate warming is progressing, there was no trend in reducing the number of frost days and slowing the first frost day, and it was found that the last frost day is delayed by 0.5 days per year.

The Estimation of Buckling Load of Pressurized Unstiffened Cylindrical Shell Using the Hybrid Vibration Correlation Technique Based on the Experimental and Numerical Approach (실험적/수치적 방법이 혼합된 VCT를 활용한 내부 압력을 받는 원통형 쉘의 좌굴 하중 예측)

  • Lee, Mi-Yeon;Jeon, Min-Hyeok;Cho, Hyun-Jun;Kim, Yeon-Ju;Kim, In-Gul;Park, Jae-Sang
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.50 no.10
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    • pp.701-708
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    • 2022
  • Since the propellant tank structure of the projectile is mainly subjected to a compressive force, there is a high risk of damage due to buckling. Large and lightweight structures such as propellant tank have a complex manufacturing process. So it requires a non-destructive test method to predict buckling load to use the structure after testing. Many studies have been conducted on Vibration Correlation Technique(VCT), which predicts buckling load using the relationship between compressive load and natural frequency, but it requires a large compressive load to predict the buckling load accurately, and it tends to decrease prediction accuracy with increasing internal pressure in structure. In this paper, we analyzed the causes of the decrease in prediction accuracy when internal pressure increases and proposed a method increasing prediction accuracy under the low compressive load for being usable after testing, through VCT combined testing and FEA result. The prediction value by the proposed method was very consistent with the measured actual buckling load.

The Role of Autophagy in Depression (우울증에서 자가소화작용의 역할)

  • Seo, Mi Kyoung;Park, Sung Woo;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.32 no.10
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    • pp.812-820
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    • 2022
  • Depression is a psychiatric disorder characterized by depressed mood, anhedonia, fatigue, and altered cognitive function, leading to a decline in daily functioning. In addition, depression is a serious and common mental illness not only in an individual's life but also in society, so it must be actively treated. Autophagy is involved in the pathophysiological mechanism of mental illness. According to a recent study, it is known that autophagy-induced apoptosis affects neuroplasticity and causes depression and that antidepressants regulate autophagy. Autophagy is a catabolic process that degradation and removes unnecessary organelles or proteins through a lysosome. And, it is essential for maintaining cellular homeostasis. Autophagy is activated in stress conditions, and depression is a stress-related disease. Stress causes damage to cellular homeostasis. Recently, although the role of autophagy mechanisms in neurons has been investigated, the autophagy of depression has not been fully studied. This review highlights the new evidence for the involvement of autophagy in the pathophysiological mechanisms and treatment of depression. To highlight the evidence, we present results from clinical and preclinical studies showing that autophagy is associated with depression. Understanding the relevance of autophagy to depression and the limitations of research suggest that autophagy regulation may provide a new direction for antidepressant development.

A Study on the Characteristics of Garden Architecture in Italian Renaissance Villa d'Este (빌라 데스테의 정원건축적 특성에 관한 연구)

  • Kim, Eun-Young;Kim, Kyu-Yeon;Choi, Jong-Hee
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.40 no.4
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    • pp.49-57
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    • 2022
  • This study was conducted with the aim of investigating the garden architectural characteristics of Villa d'Este, which occupies a major role in the exploration of the contrasting background, location, and spatial composition characteristics of Italian Renaissance gardens. The survey for the study was divided into a literature survey and a field survey, and the details are as follows. First, in the mid-to-late 16th century, the villa was built under the direction of Cardinal Ippolito d'Este, and afterwards, the ownership of the villa was restored to the Italian government in 1850 due to financial difficulties. The Villa d'Este, which suffered another damage, is now operated with many visitors after going through the restoration process. Second, in the case of location, it has the characteristics of Urbana located in the city center and has valley-type topographical conditions located at the foot of the mountain.Third, in the case of spatial composition, it is orthogonal to the axis, and each part of the garden is developed, influenced by the contrast principles such as the installation of the Cortile del Belvedere and Villa Madama in the early 16th century. The main building is located in the hills so that you can see the garden and the surrounding scenery at a glance. Fourth, among the components, there were stairs, logia, courtyard, and grotto, fountains, cascades, ponds, and vegetation such as laurels, thorn trees.

Research Trends on the Therapeutic Potential of Cordycepin, an Active Ingredient of the Insect Fungus Cordyceps spp., for the Prevention of Sarcopenia (동충하초(Cordyceps spp.)의 유효 생리활성 성분인 cordycepin의 근감소증 예방에 대한 연구 동향)

  • Kim, Sung Ok;Choi, Yung Hyun
    • Journal of Life Science
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    • v.32 no.6
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    • pp.482-490
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    • 2022
  • Sarcopenia, a geriatric and multifactorial syndrome characterized by progressive systemic skeletal muscle disorder, may be associated with many comorbidities. Sarcopenia caused by a decrease in muscle mass and muscle strength is accompanied by the aggravation of various pathological conditions, and as life expectancy increases, its prevalence will continue to increase in the future. During the aging process, chronic oxidative stress and increased inflammatory responses act as major contributors to skeletal muscle loss. In addition, disruption of autophagy and apoptosis signals associated with dysfunction of mitochondria, which are essential for energy metabolism, accelerates the loss of muscle proteins. The pharmacological effect of cordycepin, a major physiologically active substance in the genus Cordyceps, which has been widely used for the prevention and treatment of various diseases for a long time, is directly related to its antioxidant and anti-inflammatory actions. In this review, we present the correlation between apoptosis, autophagy, protein catabolism, and satellite cell activity important for muscle regeneration using cordycepin for the prevention and treatment of sarcopenia. Although there have been few studies so far on the use of cordycepin for sarcopenia, previous studies suggest that cordycepin may contribute to inhibiting the age-related weakening of mitochondrial function and blocking the breakdown of muscle proteins. In addition, the protective effect of cordycepin on muscle cell damage is considered to be closely related to its antioxidant and anti-inflammatory activities. Therefore, it is considered that more continuous basic research is needed, focusing on the molecular biological mechanism of cordycepin, which is involved in the anti-aging of muscle cells.

Management Period Setting Study of through Analysis of the Growth Amount after Planting of Deciduous Broadleaf Species Planted in Ecological Restoration Sites (생태복원지에 식재된 낙엽활엽수종의 이식 후 생장량 분석을 통한 관리기간 설정 연구)

  • Lee, Soo-Dong;Bae, Soon-Hyoung
    • Korean Journal of Environment and Ecology
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    • v.36 no.5
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    • pp.496-506
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    • 2022
  • The growth of trees planted through transplantation rapidly decreases immediately after planting due to extreme disturbances such as root cutting and crown damage. Although the growth rate is recovered as time elapses, the time required to restore the original growth varies by species. Therefore, it is necessary to set an appropriate tree management period for survival after transplantation by analyzing each species' annual growth change. In this study, we analyzed the growth amount of deciduous broad-leaf species planted in the area where the riparian ecological belt was formed and proposed the management period based on the results. Slowed growth immediately after planting is a common phenomenon due to root cutting and pruning, the pre-works performed to increase tree survival rate during the transplantation process. Afterward, the original growth rate is recovered as time passes, but the time required may vary depending on the species and planting environment. Most of the trees showed a rapid decrease in growth immediately after transplantation. After that, although it is different for each species, most of them showed a gradual recovery from 2 years onwards. The analysis of the growth rate by tree species confirmed that it took 2 to 4 years, depending on the tree species, to recover the growth level before transplantation after a rapid decrease in growth immediately after transplantation. The results suggest that improving the defect rate of planted trees is necessary to meet the project objectives: ecological restoration and pollutant reduction. It requires setting a tree management period of at least two years and creating an appropriate base environment.

A Study on the 3D Precise Modeling of Old Structures Using Merged Point Cloud from Drone Images and LiDAR Scanning Data (드론 화상 및 LiDAR 스캐닝의 정합처리 자료를 활용한 노후 구조물 3차원 정밀 모델링에 관한 연구)

  • Chan-hwi, Shin;Gyeong-jo, Min;Gyeong-Gyu, Kim;PuReun, Jeon;Hoon, Park;Sang-Ho, Cho
    • Explosives and Blasting
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    • v.40 no.4
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    • pp.15-26
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    • 2022
  • With the recent increase in old and dangerous buildings, the demand for technology in the field of structure demolition is rapidly increasing. In particular, in the case of structures with severe deformation of damage, there is a risk of deterioration in stability and disaster due to changes in the load distribution characteristics in the structure, so rapid structure demolition technology that can be efficiently dismantled in a short period of time is drawing attention. However, structural deformation such as unauthorized extension or illegal remodeling occurs frequently in many old structures, which is not reflected in structural information such as building drawings, and acts as an obstacle in the demolition design process. In this study, as an effective way to overcome the discrepancy between the structural information of old structures and the actual structure, access to actual structures through 3D modeling was considered. 3D point cloud data inside and outside the building were obtained through LiDAR and drone photography for buildings scheduled to be blasting demolition, and precision matching between the two spatial data groups was performed using an open-source based spatial information construction system. The 3D structure model was completed by importing point cloud data matched with 3D modeling software to create structural drawings for each layer and forming each member along the structure slab, pillar, beam, and ceiling boundary. In addition, the modeling technique proposed in this study was verified by comparing it with the actual measurement value for selected structure member.

Proteomic analysis for the effects of non-saponin fraction with rich polysaccharide from Korean Red Ginseng on Alzheimer's disease in a mouse model

  • Sujin Kim;Yunkwon Nam;Min-jeong Kim;Seung-hyun Kwon;Junhyeok Jeon;Soo Jung Shin;Soyoon Park;Sungjae Chang;Hyun Uk Kim;Yong Yook Lee;Hak Su Kim;Minho Moon
    • Journal of Ginseng Research
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    • v.47 no.2
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    • pp.302-310
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    • 2023
  • Background: The most common type of dementia, Alzheimer's disease (AD), is marked by the formation of extracellular amyloid beta (Aβ) plaques. The impairments of axons and synapses appear in the process of Aβ plaques formation, and this damage could cause neurodegeneration. We previously reported that non-saponin fraction with rich polysaccharide (NFP) from Korean Red Ginseng (KRG) showed neuroprotective effects in AD. However, precise molecular mechanism of the therapeutic effects of NFP from KRG in AD still remains elusive. Methods: To investigate the therapeutic mechanisms of NFP from KRG on AD, we conducted proteomic analysis for frontal cortex from vehicle-treated wild-type, vehicle-treated 5XFAD mice, and NFP-treated 5XFAD mice by using nano-LC-ESI-MS/MS. Metabolic network analysis was additionally performed as the effects of NFP appeared to be associated with metabolism according to the proteome analysis. Results: Starting from 5,470 proteins, 2,636 proteins were selected for hierarchical clustering analysis, and finally 111 proteins were further selected for protein-protein interaction network analysis. A series of these analyses revealed that proteins associated with synapse and mitochondria might be linked to the therapeutic mechanism of NFP. Subsequent metabolic network analysis via genome-scale metabolic models that represent the three mouse groups showed that there were significant changes in metabolic fluxes of mitochondrial carnitine shuttle pathway and mitochondrial beta-oxidation of polyunsaturated fatty acids. Conclusion: Our results suggested that the therapeutic effects of NFP on AD were associated with synaptic- and mitochondrial-related pathways, and they provided targets for further rigorous studies on precise understanding of the molecular mechanism of NFP.

Study on Verification of Applicability for a Warehouse Construction Site using a Fire Risk Assessment Tool (화재위험도 평가 Tool에 의한 물류창고 공사장 적용성 검증에 관한 연구)

  • YongGoo Seo;SeHong Min
    • Journal of the Society of Disaster Information
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    • v.19 no.3
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    • pp.673-688
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    • 2023
  • Purpose: Fires that occur during construction are infrequent, but cause great damage. Recently, with the growth of the logistics and distribution industry, the number of construction sites for new logistics warehouses is increasing, so it was selected as a research subject and research was conducted to reduce accidents at construction sites through the development of a fire risk assessment tool to quantitatively approach fire prevention. Method: A comprehensive fire risk assessment tool was accumulated by classifying the work in progress, classifying combustibles and ignition sources by grade, excluding air (oxygen), which is difficult to control, and additionally substituting evacuation safety. Result: Using the developed and proposed fire risk evaluation tool, excavation work with low fire risk, facility construction with medium fire risk, and finishing work with high fire risk were sampled to derive the result (CGI). Conclusion: In this study, it was possible to establish specific preventive measures and evaluate evacuation safety by controlling physical conditions (combustibles) and energy conditions (ignition sources) according to the risk assessment by developing a tool that can evaluate the risk of 14fire occurrence at construction sites. It is expected that in the future, through the application of the fire risk evaluation tool at construction sites, it will be provided as a criterion for establishing a process plan that can reduce risk and evaluating the adaptability of firefighting equipment.14

Phenomenological Study on the Victim's Life after May 18 1980 and the Experience of Testimony Therapy (5·18민주화운동 참여자의 80년 5월 이후 삶과 증언치료 경험에 관한 현상학적 연구)

  • Moonsun Kim ;Moonminseo Kang
    • Korean Journal of Culture and Social Issue
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    • v.23 no.4
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    • pp.451-473
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    • 2017
  • This study explores the aftermath of state violence and the meaning of its healing by analyzing testimony therapy designed to deal with trauma of the victims of May 18 democratization movement("May 18"). In order to have a point of view that May 18 had catastrophic impacts on many individuals and communities and to observe the after-effects of such event to individuals' lives, this study analyzed the contents of testimony therapy sessions of four people who were tortured, arrested and detained after their participating in May 18 in 1980. The experiences of those participants with their testimony therapy and the interactions they had with the audience during the sessions made sure what are the key factors to healing the trauma from state violence. Nineteen topics were drawn from analyzing the statements made in the therapy process, and out of them, seven subjects below were chosen as the most significant; 'repetitive pain', 'social and economic damage', 'isolation and disconnection', 'transition of suffering to other generations', and 'Safety', 'healing through connections', 'obligation as a survivor'. Based on its findings, this study also examined the characteristics of trauma caused by state violence and made suggestions for healing such trauma.