• Title/Summary/Keyword: local collapse

Search Result 212, Processing Time 0.027 seconds

A Comparative Study of Satisfaction and Pro-environmental Behavior on the Jeju Olle among Jeju Residents and Visitors (제주도민과 제주방문 도보여행객의 제주올레에 대한 만족도와 친환경 행동 비교)

  • You, Won-Hee;Seo, Se-Jin
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.35 no.1
    • /
    • pp.83-89
    • /
    • 2017
  • The Jeju Olle Trail Route No. 1 has opened in 2007, and over one million visitors per year trek total of 26 Olle trails throughout the island of Jeju as of 2017. The Olle trekking is one of eco-friendly tourism activities in the era of social issues with environmental collapse and threats. Up until now, studies on the Jeju Olle trail are focused on the visitors while the studies on residents who are the other major pillar of Jeju Olle trail have been limited. The study aims to compare the visit types, satisfaction level and pro-environmental behaviors between the visitors and residents on Jeju Olle trails. Total of 290 survey was collected in three month period from December, 2016 to February, 2017. The survey result indicates the Jeju residents trek the Jeju Olle in a larger group than the Jeju Olle visiting trekkers and show lower level in the visit satisfaction and pro-environmental behaviors. The noticeable lower level in the pro-environmental behaviors of residents can directly connect to the issue of Jeju environment as a whole, and the continuing environmental education program and promotion for residents to improve the pro-environmental behavior level is essential.

Analysis of Village Safety Index using Accessibility to Public Facilities (공공시설 접근성을 통한 마을단위 안전지수 분석)

  • Jeon, Jeongbae;Kim, Solhee;Suh, Kyo;Yoon, Seongsoo
    • Journal of Korean Society of Rural Planning
    • /
    • v.22 no.2
    • /
    • pp.121-129
    • /
    • 2016
  • A disaster can be defined in many ways based on perspectives, in addition, its types are able to classify differently by various standards. Considering the different perspectives, the disaster can be occurred by natural phenomenon that is like typhoon, earthquake, flood, and drought, and by the accident that is like collapse of facilities, traffic accidents, and environmental pollution, etc. Into the modern society, moreover, the disaster includes the damages by diffusion of epidemic and infectious disease in domestic animals. The disaster was defined by natural and man-made hazards in the past. As societies grew with changes of paradigm, social factors have been included in the concept of the disaster according to new types unexpected by new disease and scientific technology. Change the concept of social disasters, Ministry of Public Safety and Security (MPSS) has provided the regional safety index, which measures the safety level of a local government. However, this regional safety index has some limitation to use because this index provides the information for city unit which is a unit of administrative districts of urban. Since these administrative districts units are on a different level with urban and rural areas, the regional safety index provided by MPSS is not be able to direct apply to the rural areas. The purpose of this study is to determine the regional safety index targeting rural areas. To estimate the safety index, we was used for 3 indicators of the MPSS, a fire, a crime, and an infectious disease which are evaluable the regional safety index using an accessibility analysis. For determining the regional safety index using accessibility from community centers to public facilities, the safety index of fire, crime, and infectious disease used access time to fire station, police office, and medical facility, respectively. An integrated Cheongju, targeting areas in this study, is mixed region with urban and rural areas. The results of regional safety index about urban and rural areas, the safety index in rural area is relatively higher than in the urban. Neverthless the investment would be needed to improve the safety in the rural areas.

A experimental Feasibility of Magnetic Resonance Based Monitoring Method for Underground Environment (지하 환경 감시를 위한 자기공명 기반 모니터링 방법의 타당성 연구)

  • Ryu, Dong-Woo;Lee, Ki-Song;Kim, Eun-Hee;Yum, Byung-Woo
    • Tunnel and Underground Space
    • /
    • v.28 no.6
    • /
    • pp.596-608
    • /
    • 2018
  • As urban infrastructure is aging, the possibility of accidents due to the failures or breakdowns of infrastructure increases. Especially, aging underground infrastructures like sewer pipes, waterworks, and subway have a potential to cause an urban ground sink. Urban ground sink is defined just as a local and erratic collapse occurred by underground cavity due to soil erosion or soil loss, which is separated from a sinkhole in soluble bedrock such as limestone. The conventional measurements such as differential settlement gauge, inclinometer or earth pressure gauge have a shortcoming just to provide point measurements with short coverage. Therefore, these methods are not adequate for monitoring of an erratic subsidence caused by underground cavity due to soil erosion or soil loss which occurring at unspecified time and location. Therefore, an alternative technology is required to detect a change of underground physical condition in real time. In this study, the feasibility of a novel magnetic resonance based monitoring method is investigated through laboratory tests, where the changes of path loss (S21) were measured under various testing conditions: media including air, water, and soil, resonant frequency, impedance, and distances between transmitter (TX) and receiver (RX). Theoretically, the transfer characteristic of magnetic field is known to be independent of the density of the medium. However, the results of the test showed the meaningful differences in the path loss (S21) under the different conditions of medium. And it is found that the reflection coefficient showed the more distinct differences over the testing conditions than the path loss. In particular, input reflection coefficient (S11) is more distinguishable than output reflection coefficient (S22).

Estimation of Employment Creation Center considering Spatial Autocorrelation: A Case of Changwon City (공간자기상관을 고려한 고용창출중심지 추정: 창원시 사례를 중심으로)

  • JEONG, Ha-Yeong;LEE, Tai-Hun;HWANG, In-Sik
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.25 no.1
    • /
    • pp.77-100
    • /
    • 2022
  • In the era of low growth, many provincial cities are experiencing population decline and aging. Population decline phenomena such as reduction of productive manpower, reduction of finances, deterioration of quality of life, and collapse of the community base are occurring in a chain and are being pushed to the brink of extinction of the cities. This study aims to propose a methodology to objectively estimate the employment creation centers and setting the basic unit of industrial-centered zoning by applying spatial statistical techniques and GIS for the application of the compact city plan as an efficient spatial management policy in a city with a declining population. In details, based on reviewing previous studies on compact city, 'employment complex index(ECI)' were defined considering the number of workers, the number of settlers, and the area of development land, the employment creation center was estimated by applying the 'Local Moran's I' and 'Getis-Ord's Hot-Spot Analysis'. As a case study, changes in the four years of 2013, 2015, 2017, and 2019 were compared and analyzed for Changwon City. As a result, it was confirmed that the employment creation center is becoming compacted and polycentric, which is a significant result that reflects the actual situation well. This results provide the basic data for functional and institutional territorial governance for the regional revitalization platform, and provide meaningful information necessary for spatial policy decision-making, such as population reduction, regional gross domestic product, and public facility arrangement that can respond to energy savings, transportation plans, and medical and health plans.

Prediction of Scour Depth Using Incorporation of Cluster Analysis into Artificial Neural Networks (인공신경망모형과 군집분석을 이용한 교각 세굴심 예측)

  • Lee, Chang-Hwan;Ahn, Jae-Hyun;Lee, Joo Heon;Kim, Tea-Woong
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.29 no.2B
    • /
    • pp.111-120
    • /
    • 2009
  • A local scour around a bridge pier is known as one of important factors of bridge collapse. Two approaches are usually used in estimating a scour depth in practice. One is to use empirical formulas, and the other is to use computational methods. But the use of empirical formulas is limited to predict a scour depth under similar conditions to which the formulas were derived. Computational methods are currently too expensive to be applied to practical engineering problems. This study presented the application of artificial neural networks (ANN) to the prediction of a scour depth around a bridge pier at an equilibrium state. This study also investigated various ANN algorithms for estimating a scour depth, such as Backpropagation Network, Radial Basis Function Network, and Generalized Regression Network. Preliminary study showed that ANN models resulted in very wide range of errors in predicting a scour depth. To solve this problem this study incorporated cluster analysis into ANN. The incorporation of cluster analysis provided better estimations of scour depth up to 42% compared with other approaches.

Effect of the initial imperfection on the response of the stainless steel shell structures

  • Ali Ihsan Celik;Ozer Zeybek;Yasin Onuralp Ozkilic
    • Steel and Composite Structures
    • /
    • v.50 no.6
    • /
    • pp.705-720
    • /
    • 2024
  • Analyzing the collapse behavior of thin-walled steel structures holds significant importance in ensuring their safety and longevity. Geometric imperfections present on the surface of metal materials can diminish both the durability and mechanical integrity of steel shells. These imperfections, encompassing local geometric irregularities and deformations such as holes, cavities, notches, and cracks localized in specific regions of the shell surface, play a pivotal role in the assessment. They can induce stress concentration within the structure, thereby influencing its susceptibility to buckling. The intricate relationship between the buckling behavior of these structures and such imperfections is multifaceted, contingent upon a variety of factors. The buckling analysis of thin-walled steel shell structures, similar to other steel structures, commonly involves the determination of crucial material properties, including elastic modulus, shear modulus, tensile strength, and fracture toughness. An established method involves the emulation of distributed geometric imperfections, utilizing real test specimen data as a basis. This approach allows for the accurate representation and assessment of the diversity and distribution of imperfections encountered in real-world scenarios. Utilizing defect data obtained from actual test samples enhances the model's realism and applicability. The sizes and configurations of these defects are employed as inputs in the modeling process, aiding in the prediction of structural behavior. It's worth noting that there is a dearth of experimental studies addressing the influence of geometric defects on the buckling behavior of cylindrical steel shells. In this particular study, samples featuring geometric imperfections were subjected to experimental buckling tests. These same samples were also modeled using Finite Element Analysis (FEM), with results corroborating the experimental findings. Furthermore, the initial geometrical imperfections were measured using digital image correlation (DIC) techniques. In this way, the response of the test specimens can be estimated accurately by applying the initial imperfections to FE models. After validation of the test results with FEA, a numerical parametric study was conducted to develop more generalized design recommendations for the stainless-steel shell structures with the initial geometric imperfection. While the load-carrying capacity of samples with perfect surfaces was up to 140 kN, the load-carrying capacity of samples with 4 mm defects was around 130 kN. Likewise, while the load carrying capacity of samples with 10 mm defects was around 125 kN, the load carrying capacity of samples with 14 mm defects was measured around 120 kN.

Analysis of Growth-Decline Type and Factors Influencing Growth Commercial Area Using Sales Data in Alley Commercial Area - Before and After COVID-19 - (골목상권 매출액 데이터를 활용한 성장-쇠퇴 유형화와 성장상권 영향요인 분석 - 코로나19 전후를 대상으로 -)

  • Jiwan Park;Leebom Jeon;Seungil Lee
    • Journal of the Korean Regional Science Association
    • /
    • v.39 no.1
    • /
    • pp.53-66
    • /
    • 2023
  • Due to COVID-19, the external activities of urban residents have greatly shrunk, causing a lot of damage to the commercial district, such as a decrease in population and sales. The downturn in commercial districts means the collapse of the infrastructure of the national economy, and can have serious side effects on the local economy and individual lives. Therefore, it is necessary to look at the alley commercial area, which is closely related to the national local economy, and pay attention to the damage and stagnation of the alley commercial area where small business owners are concentrated. The purpose of this study is to classify alley commercial districts into growth commercial districts and decline commercial districts by using commercial sales time series data and DTW time series group analysis for the pre- and post-COVID-19 period. The main findings of the study are as follows. First, using the time series data on commercial sales before and after COVID-19, the alley commercial districts were divided into growth commercial districts and decline commercial districts, and it was confirmed that the distribution of growth commercial districts and decline commercial districts was regionally different. Therefore, it is necessary to actively manage commercial districts in areas where many declining commercial districts are distributed, and it is required to prepare policies for each region in consideration of the spatial distribution of declining commercial districts. Second, during the COVID-19 period, face-to-face essential industries, density of guest facilities, and population density negatively affected the sustainability of commercial districts, which is the opposite of previous studies. This is the result of empirically confirming the specificity of the COVID-19 period and the negative effects of the integrated economy, and can be used as basic data for effective commercial district management and policy preparation in the event of a national disaster in the future. Third, the characteristics of the background of the commercial district had a significant effect on the sustainability of the commercial district, and the negative effect of the attracting facilities inducing population concentration in the background area was found. This suggests that it is necessary to consider the characteristics of the background as well as the inside of the commercial district when establishing policies to revitalize the commercial district and support small business owners in a national disaster situation.

An Analysis of the Policy-Knowledge-Power Dynamics in Higher Education Reform in Transitional Myanmar (전환기 미얀마 정치사회변화와 신(新)고등교육 개혁: 정책·지식·권력의 역동을 중심으로)

  • Hong, Moon-Suk
    • Korean Journal of Comparative Education
    • /
    • v.28 no.3
    • /
    • pp.135-159
    • /
    • 2018
  • This thesis compares and analyzes the dynamics between policy, knowledge and power of Myanmar's higher education development. The papers begins by exploring the dynamics during the Socialist Military Regime(1962~1988), the Collapse of Higher Education Era(1988~2010), Thein Sein's Reform Era(2010~2015) and the current Aung San Suu Kyi's Civilian Era(2015~Now). By highlighting recent dramatic policy changes, the article argues that the policy discourse on the subject of internationalization of higher education and the technocratization of education development policy by the current Civilian Government in its new policy discourse, that resulted in the active participation as well as the contributions of international donors has directly impacted on the policy dynamics around the Comprehensive Education Sector Review and the introduction of the National Education Strategic Plan 2016~2020. Further, by examining complex interaction between the current domestic education stakeholders and international donors in education sector in Myanmar, this thesis argues that the new analytical framework on the understanding of policy dynamics in developing countries goes beyond the national level. The paper argues that there needs to be broadening of the analytical framework towards the multidimensional analysis perspective that includes global, national as well as local level policy, knowledge and power dynamics in Myanmar's dynamically changing higher education sector.

New Government's Responsibility and Achievement in Records & Archives Management (공공기록물 관리에 있어 이명박정부의 책임과 '업적')

  • Lee, Seung-Hwi
    • The Korean Journal of Archival Studies
    • /
    • no.18
    • /
    • pp.257-280
    • /
    • 2008
  • The purpose of this paper is reviewing the hot issue called 'draining away the presidential records' case occurred recently and finding the root cause why the state of affairs has been happened in Korea. Though the presidential records management law ensures the rights for the prior president to view his presidential records, the prior president has copied his presidential records produced while in office and moved to his private house at his retirement. He might have interpreted his right to his presidential records too broadly and done the 'draining away' them. There was a motive why the prior president did that at that time. The reason was because the National Archives didn't guarantee the services for right viewing the records to him who wanted to review his records from right after his retirement. The National Archives have judged the draining away the prior presidential records as illegal and accused a few public servants suspected to be responsible for the affairs. The formal accuser is the National Archives, but the actual accuser might be the current Presidential Secretariat. Whatever the results of juristic judgement are, the reason why the records management field should focus and treat this case importantly is that the collapse possibility of the protection wall needed essentially and critically to the Presidential records becomes very high. The root cause of this case might exist in the fact that the records and archives management organizations have not owned the political independence. But the National Archives has submitted the revised bill of the public records and archives management law which lower the position of the National Records Management Committee controlled under from the Prime Minister to the Ministry of Administration and Security. It might be hot concern that the records and archives management organizations have difficulty for keeping the political independence if the revision would be passed. Besides the political independence factor, the most important factor needed for the right records management is the establishing the professional specificity of records management. The specific action for the establishing professional specificity would be employing of specialists and introducing the open official appointment. But it was found from the reorganization after the governmental change that the professional specificity of the National Archives have been reduced. Although the policies introduced by the new government are worrying, it might be an inheritance from the prior government. If new government would build establish the institution for the political independence of the records and archives management organizations and expand the employment of the records management professions to the local government, these affairs can be not only the responsibilities but also the achievements of the new government.

Brief Introduction of Research Progresses in Control and Biocontrol of Clubroot Disease in China

  • He, Yueqiu;Wu, Yixin;He, Pengfei;Li, Xinyu
    • 한국균학회소식:학술대회논문집
    • /
    • 2015.05a
    • /
    • pp.45-46
    • /
    • 2015
  • Clubroot disease of crucifers has occurred since 1957. It has spread to the whole China, especially in the southwest and nourtheast where it causes 30-80% loss in some fields. The disease has being expanded in the recent years as seeds are imported and the floating seedling system practices. For its effective control, the Ministry of Agriculture of China set up a program in 2010 and a research team led by Dr. Yueqiu HE, Yunnan Agricultural University. The team includes 20 main reseachers of 11 universities and 5 institutions. After 5 years, the team has made a lot of progresses in disease occurrence regulation, resources collection, resistance identification and breeding, biological agent exploration, formulation, chemicals evaluation, and control strategy. About 1200 collections of local and commercial crucifers were identified in the field and by artificiall inoculation in the laboratories, 10 resistant cultivars were breeded including 7 Chinese cabbages and 3 cabbages. More than 800 antagostic strains were isolated including bacteria, stretomyces and fungi. Around 100 chemicals were evaluated in the field and greenhouse based on its control effect, among them, 6 showed high control effect, especially fluazinam and cyazofamid could control about 80% the disease. However, fluzinam has negative effect on soil microbes. Clubroot disease could not be controlled by bioagents and chemicals once when the pathogen Plasmodiophora brassicae infected its hosts and set up the parasitic relationship. We found the earlier the pathogent infected its host, the severer the disease was. Therefore, early control was the most effective. For Chinese cabbage, all controlling measures should be taken in the early 30 days because the new infection could not cause severe symptom after 30 days of seeding. For example, a biocontrol agent, Bacillus subtilis Strain XF-1 could control the disease 70%-85% averagely when it mixed with seedling substrate and was drenching 3 times after transplanting, i.e. immediately, 7 days, 14 days. XF-1 has been deeply researched in control mechanisms, its genome, and development and application of biocontrol formulate. It could produce antagonistic protein, enzyme, antibiotics and IAA, which promoted rhizogenesis and growth. Its The genome was sequenced by Illumina/Solexa Genome Analyzer to assembled into 20 scaffolds then the gaps between scaffolds were filled by long fragment PCR amplification to obtain complet genmone with 4,061,186 bp in size. The whole genome was found to have 43.8% GC, 108 tandem repeats with an average of 2.65 copies and 84 transposons. The CDSs were predicted as 3,853 in which 112 CDSs were predicted to secondary metabolite biosynthesis, transport and catabolism. Among those, five NRPS/PKS giant gene clusters being responsible for the biosynthesis of polyketide (pksABCDEFHJLMNRS in size 72.9 kb), surfactin(srfABCD, 26.148 kb, bacilysin(bacABCDE 5.903 kb), bacillibactin(dhbABCEF, 11.774 kb) and fengycin(ppsABCDE, 37.799 kb) have high homolgous to fuction confirmed biosynthesis gene in other strain. Moreover, there are many of key regulatory genes for secondary metabolites from XF-1, such as comABPQKX Z, degQ, sfp, yczE, degU, ycxABCD and ywfG. were also predicted. Therefore, XF-1 has potential of biosynthesis for secondary metabolites surfactin, fengycin, bacillibactin, bacilysin and Bacillaene. Thirty two compounds were detected from cell extracts of XF-1 by MALDI-TOF-MS, including one Macrolactin (m/z 441.06), two fusaricidin (m/z 850.493 and 968.515), one circulocin (m/z 852.509), nine surfactin (m/z 1044.656~1102.652), five iturin (m/z 1096.631~1150.57) and forty fengycin (m/z 1449.79~1543.805). The top three compositions types (contening 56.67% of total extract) are surfactin, iturin and fengycin, in which the most abundant is the surfactin type composition 30.37% of total extract and in second place is the fengycin with 23.28% content with rich diversity of chemical structure, and the smallest one is the iturin with 3.02% content. Moreover, the same main compositions were detected in Bacillus sp.355 which is also a good effects biocontol bacterial for controlling the clubroot of crucifer. Wherefore those compounds surfactin, iturin and fengycin maybe the main active compositions of XF-1 against P. brassicae. Twenty one fengycin type compounds were evaluate by LC-ESI-MS/MS with antifungal activities, including fengycin A $C_{16{\sim}C19}$, fengycin B $C_{14{\sim}C17}$, fengycin C $C_{15{\sim}C18}$, fengycin D $C_{15{\sim}C18}$ and fengycin S $C_{15{\sim}C18}$. Furthermore, one novel compound was identified as Dehydroxyfengycin $C_{17}$ according its MS, 1D and 2D NMR spectral data, which molecular weight is 1488.8480 Da and formula $C_{75}H_{116}N_{12}O_{19}$. The fengycin type compounds (FTCPs $250{\mu}g/mL$) were used to treat the resting spores of P. brassicae ($10^7/mL$) by detecting leakage of the cytoplasm components and cell destruction. After 12 h treatment, the absorbencies at 260 nm (A260) and at 280 nm (A280) increased gradually to approaching the maximum of absorbance, accompanying the collapse of P. brassicae resting spores, and nearly no complete cells were observed at 24 h treatment. The results suggested that the cells could be lyzed by the FTCPs of XF-1, and the diversity of FTCPs was mainly attributed to a mechanism of clubroot disease biocontrol. In the five selected medium MOLP, PSA, LB, Landy and LD, the most suitable for growth of strain medium is MOLP, and the least for strains longevity is the Landy sucrose medium. However, the lipopeptide highest yield is in Landy sucrose medium. The lipopeptides in five medium were analyzed with HPLC, and the results showed that lipopeptides component were same, while their contents from B. subtilis XF-1 fermented in five medium were different. We found that it is the lipopeptides content but ingredients of XF-1 could be impacted by medium and lacking of nutrition seems promoting lipopeptides secretion from XF-1. The volatile components with inhibition fungal Cylindrocarpon spp. activity which were collect in sealed vesel were detected with metheds of HS-SPME-GC-MS in eight biocontrol Bacillus species and four positive mutant strains of XF-1 mutagenized with chemical mutagens, respectively. They have same main volatile components including pyrazine, aldehydes, oxazolidinone and sulfide which are composed of 91.62% in XF-1, in which, the most abundant is the pyrazine type composition with 47.03%, and in second place is the aldehydes with 23.84%, and the third place is oxazolidinone with 15.68%, and the smallest ones is the sulfide with 5.07%.

  • PDF