• Title/Summary/Keyword: impact damages

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A Damage Measurement of Steel Beam using PZT Sensor (PZT센서를 이용한 철골보 손상계측)

  • Seo, Hye-Won;Park, Min-Suk;Lee, Swoo-Heon;Shin, Kyung-Jae
    • Journal of Korean Society of Steel Construction
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    • v.22 no.5
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    • pp.477-485
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    • 2010
  • Various monitoring sensors are used to predict and detect structural damage. Smart sensors, such as glass-fiber sensors, PZT, and MEMS, among others, have replaced traditional sensors. They are now being used in many areas. This study aims to predict the damage by measuring the PZT voltage attached on the specimen by the applied impact load. In the experiment to detect damages in beam connection, simple $H-400{\times}200{\times}8{\times}13$ beams were spliced with bolts. The results of FFT between PZT sensor and accelrometer were compared to measure the sensitivity of the PZT sensor. The damage to the beam was presumed by loosening the bolt, and then the damage measurement was accompanied. Secondly, a steel $PL600{\times}65{\times}5.8$ plate beam was fabricated for the purpose of experimenting on damage measurement. Impact loading test on three different locations was carried out. Damage width varied between 6~42mm on both sides by cutting, using a steel saw. The ratio of frequencies before and after the damage was computed to quantify the damage level by using FFT, and the change in mode pattern with the increased damage was investigated to measure the damage.

Emergy Evaluation of Typhoon Maemi in Busan (태풍 매미가 부산시에 미치는 영향에 대한 에머지 평가)

  • Park, KyungMin;Kim, Dong-Myung;Lee, Suk Mo
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.20 no.1
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    • pp.18-25
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    • 2017
  • Damage of both life and property has been increased by natural disaster under the influence of climate change, thus many natural disaster vulnerability researches have been carried out to make adaptation policy and impact assessment of climate change recently. Their method for assessing vulnerability usually have used proxy variables for making vulnerability indices. However, because their results were too qualitative and relative it tends to be hard to make absolute comparison and establish standard of prevention or adaptation ability. Accordingly, this study aimed at quantifying natural disaster vulnerability using emergy through recognizing disaster as the relations between order and disorder by system approach. As a result, ordering energy (4.66E+22 sej/yr) and ordered structure (1.98E+22 sej) of Busan in 2003 and disordering energy (7.80E+18 sej), disordered parts (4.55E+20 sej) and rebuilding energy (3.87E+20 sej) by typhoon Maemi were analysed. And then, this was compared with Hurricane Andrew in Dade County. Through this comparison, if the prevention ability of Busan increases, disordered parts can be reduced against the more powerful disordering energy. Also, prevention for additional damages by disaster is needed to practical rebuilding action. In conclusion, it was able to figure out the impact of disaster quantitatively by natural systems and urban systems showing as common measure. Based on this study and further research to make effective prevention for how much prevention ability should be increased will contribute to producing the scientific data for disaster management policy in future.

Littoral Drift by the combined impact of Wind, Wave and Current ant the coastal Development Environment (해안개발환경하에서 바람 ${\cdot}$ 파랑 ${\cdot}$ 흐름의 중첩에 의한 연안표사)

  • Lee, Seung-Chul;Lee, Joong-Woo;Kim, Ki-Dam;Kang, Seok-Jin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2007.12a
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    • pp.141-142
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    • 2007
  • In recent years, the rate of mean sea level rise is increasing rapidly from the phenomena of global warming, together with the increasing trend of the storm scale. The issue of sea level rise is multifaceted and produces a range of environmental problems. Especially, high tides and the tidal currents become higher, and wave base increases, so the energy received at the coastal boundary may increase. This brings that many coastal environments go into disequilibrium, such as damages to the structures, erosion, and deposition Similarly it was known that the problems of nearshore processes and damage of berth and counter facilities during storm period had appeared at the small fishery port. Here we try to analyze the impact of the rearrangement of counter facilities and berth layout adopted for tranquility of its'inner harbor. Because this harbor is being connected to channel and open sea, the rearrangement of the structures might affect to the current speed and direction and wave height, so do to the sea bottom undulation. Therefore, we made model test for the several layouts of the berth and breakwater in this area.

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Trail Deterioration and Distribution Characteristics of South-North Green Corridor in Incheon, Korea - A Case Study of Mountainous Type Urban Natural Parks - (인천시 남북녹지축 탐방로의 분포와 훼손특성 -산지형 도시자연공원을 사례로-)

  • Cho Woo;Oh Kang-Im;Bae Joong-Nam
    • Korean Journal of Environment and Ecology
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    • v.18 no.4
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    • pp.359-368
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    • 2004
  • The purpose of this study is to examine distribution and damages of the trails of inquiry of urban natural parks. Those parks were located at south-north green corridor at Incheon being mountainous type of urban natural parks that were core area of urban ecosystem preservation to of urban natural parks that citizens recently made use of them as nature experience type of leisure and recreation place from time to time, and to supply basic material deciding on the ways to improve the trails of nature preservation type. The survey sites included Geyang Park, Baekma Park, Yaksa Park, Munhak Park and Cheongryang Park. The number of main trails was 42 at Geyang Park, 43 at Baekma Park, 9 at Yaksa Park, 28 at Munhak Park, and 22 at Cheongryang Park, and it was excessively more than optimum needed: The number of branch trails of the parks seemed to increase. The bared trail width in average of the roads was 3.5m, while maximum depth in average was 21.3cm. The trails were thought to be deteriorated rapidly without systematic maintenance. The 5th and 6th grade of the impact rating class that required restoration because of serious deterioration occupied 19.6∼78.0%. Based on the findings, the study suggested ways to improve and manage the trails of inquiry of urban natural parks that were placed at south-north green corridor at Incheon.

Multiple-biometric Attributes of Biomarkers and Bioindicators for Evaluations of Aquatic Environment in an Urban Stream Ecosystem and the Multimetric Eco-Model (도심하천 생태계의 수환경 평가를 위한 생지표 바이오마커 및 바이오인디케이터 메트릭 속성 및 다변수 생태 모형)

  • Kang, Han-Il;Kang, Nami;An, Kwang-Guk
    • Journal of Environmental Impact Assessment
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    • v.22 no.6
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    • pp.591-607
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    • 2013
  • The objectives of the study were to evaluate the aquatic environment of an urban stream using various ecological parameters of biological biomarkers, physical habitat quality and chemical water quality and to develop a "Multimetric Eco-Model" ($M_m$-E Model) for the ecosystem evaluations. For the applications of the $M_m$-E model, three zones including the control zone ($C_Z$) of headwaters, transition zone ($T_Z$) of mid-stream and the impacted zone ($I_Z$) of downstream were designated and analyzed the seasonal variations of the model values. The biomarkers of DNA, based on the comet assay approach of single-cell gel electrophoresis (SCGE), were analyzed using the blood samples of Zacco platypus as a target species, and the parameters were used tail moment, tail DNA(%) and tail length (${\mu}m$) in the bioassay. The damages of DNA were evident in the impacted zone, but not in the control zone. The condition factor ($C_F$) as key indicators of the population evaluation indicator was analyzed along with the weight-length relation and individual abnormality. The four metrics of Qualitative Habitat Evaluation Index (QHEI) were added for the evaluations of physical habitat. In addition, the parameters of chemical water quality were used as eutrophic indicators of nitrogen (N) and phosphorus (P), chemical oxygen demand (COD) and conductivity. Overall, our results suggested that attributes of biomarkers and bioindicators in the impacted zone ($I_Z$) had sensitive response largely to the chemical stress (eutrophic indicators) and also partially to physical habitat quality, compared to the those in the control zone.

Vegetation Classification and Distributional Pattern in Damyang Riverine Wetland (담양하천습지의 식생유형과 분포양상)

  • Ahn, Kyunghwan;Lim, Jeongcheol;Lee, Youlkyung;Choi, Taebong;Lee, Kwangseok;Im, Myoungsoon;Go, Youngho;Suh, Jaehwa;Shin, Youngkyu;Kim, Myungjin
    • Journal of Environmental Impact Assessment
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    • v.25 no.2
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    • pp.89-102
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    • 2016
  • Damyang riverine wetland was designated as a wetland protected area in 2004; that is located in the Yeongsan river mainstream. Total 30 phytosociological releves at field studies were classified with 22 vegetation types including of 101 species (unidentified 1 species). Legends of actual vegetation map were separated by 6 types; riparian forest, substitute vegetation, synanthropic vegetation, wet meadow vegetation, open water, an area of wetland vegetation is about 35 % ($386,841.86m^2$). Results of this study area as follows. The plant society of Damyang riverine wetland was conjectured that it was formed by rapidly water environment change with installed weir on the upstream of protected area and operating of Damyang dam on top of the basin. Until recently, the terrace land on the river was used to cultivate, but that would be formed fallow vegetation scenery on riverfront caused by no cultivation after designated protected area. Paspalum distichum var. indutum community designated as invasive alien plant by Korea Ministry of Environment was widely developed and Myriophyllum spicatumunrecorded in the country as newly alien species was discovered in the study zone. The plants as lapped over developing environment for Leersia japonica must be occupied habitat of native plant species having similar niche. The various plant society in Damyang riverine wetland should be developed because of environmental changes, disturbances and damages of stream.

Consequences of Water Induced Disasters to Livelihood Activities in Nepal

  • Gurung, Anup;Karki, Arpana;Karki, Rahul;Bista, Rajesh;Oh, Sang-Eun
    • Korean Journal of Environmental Agriculture
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    • v.31 no.2
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    • pp.129-136
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    • 2012
  • BACKGROUND: The changes in the climatic conditions have brought potentially significant new challenges, most critical are likely to be its impact on local livelihoods, agriculture, biodiversity and environments. Water induced disasters such as landslides, floods, erratic rain etc., are very common in developing countries which lead to changes in biological, geophysical and socioeconomic elements. The extent of damages caused by natural disasters is more sever in least developing countries. However, disasters affect women and men differently. In most of the cases women have to carry more burden as compared to their male counterpart during the period of disasters. METHODS AND RESULTS: This study examines the impact of disasters on the local livelihood especially agriculture and income generating activities of women in three districts of Nepal. The study uses the primary data collected following an exploratory approach, based on an intensive field study. The general findings of the study revealed that women had to experience hard time as compared to their male counterpart both during and after the disaster happen. Women are responsible for caring their children, collecting firewood, fetching water, collecting grass for livestock and performing household chores. Whereas, men are mainly involved in out-migration and remained out-side home most of the time. After the disaster occurred, most of the women had to struggle to support their lives as well as had to work longer hours than men during reconstruction period. Nepal follows patriarchal system and men can afford more leisure time as compared to women. During the disaster period, some of the households lost their agricultural lands, livestock and other properties. These losses created some additional workload to women respondent, however at the same time; they learn to build confidence, self-respect, self-esteem, and self-dependency.Although Nepal is predominantly agriculture, majority of the farmers are at subsistence level. In addition, men and women have different roles which differ with the variation in agro-production systems. Moreover women are extensively involved in agricultural activities though their importances were not recognized. Denial of land ownership and denial of access to resources as well as migration of male counterparts are some of the major reasons for affecting the agricultural environments for women in Nepal. CONCLUSION: The shelter reconstruction program has definitely brought positive change in women's access to decision making. The gradual increase in number of women respondent in access to decision making in different areas is a positive change and this has also provided them with a unique opportunity to change their gendered status in society.Furthermore, the exodus out-flow of male counterparts accelerated the additional burden and workload on women.

Distribution of Pyroclastic Density Currents Determined by Numerical Model at Mt. Baekdu Volcano (백두산 화산에서 수치모형 분석에 의한 화쇄류의 영향 범위)

  • Yun, Sung-Hyo;Chang, Cheolwoo;Kim, Sunkyeong
    • The Journal of the Petrological Society of Korea
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    • v.23 no.4
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    • pp.351-366
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    • 2014
  • We assumed the situation where an eruption column had been formed by the explosive Plinian eruption from Mt. Baekdu and that the collapse of eruption column had caused pyroclastic density currents to occur. Based on this assumption, we simulated by using a Titan2D model. To find out about the range of the impacts of pyroclastic density currents by volcanic eruption scenarios, we studied the distance for the range of the impacts by VEIs. To compare the results by each volcanic eruption scenario, we set the location of the vent on the 8-direction flank of the outer rim and on the center of the caldera, the internal friction angle of the pyroclastic density currents as $35^{\circ}$, the bed friction angle as $16^{\circ}$. We set the pile height of column collapse and the vent diameter with various VEIs. We properly assumed the height of the column collapse, the diameter of the vent, the initial rates of the column collapse and the simulation period, based on the VEIs, gravity and the volume of the collapsed volcanic ash. According to the comparative analysis of the simulation results based on the increase of the eruption, the higher VEI by the increase of eruption products, the farther the pyroclastic density currents disperse. To the northwest from the vent on the northeast slope of the outer rim of the caldera, the impact range was 3.3 km, 4.6 km, 13.2 km, 24.0 km, 50.2 km, 83.4 km or more from VEI=2 to VEI=7, respectively. Once the database has been fully constructed, it can be used as a very important material in terms of disaster prevention and emergency management, which aim to minimize human and material damages in the vicinity of Mt. Baekdu when its eruption causes the pyroclastic density currents to occur.

Organizational 'Rules' that Impede or Promote Effective Social Work Practice: How Social Workers Are Affected by the Rules (사회복지기관의 '숨은 규칙' 확인 및 그 영향력 측정을 통한 사회복지실천 내실화 방안)

  • Um, Myung-Yong
    • Korean Journal of Social Welfare
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    • v.52
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    • pp.171-200
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    • 2003
  • Social workers' behaviors in their organizations are governed not only by explicit rules but by implicit rules. This study aimed to measure the extent that the implicit rules exist in social work agencies, and to assess the impact of the implicit rules on the degree of social workers' devotion, burnout, and satisfaction in their own work places. This study also endeavored to search any sort of sanctions that agencies apply against workers who refused to follow implicit rules in their organizations, along with any harms and/or benefits which organizations may experience according to the extent that the implicit rules exist. The results showed that the implicit rules do not exist so much in social work agencies in Korea. Not so many sanctions in the organizations were not found against workers who violated the implicit rules. The amount of implicit rules, however, affected the degree of damages that organizations sustained. The more implicit rules exist in the organizations, the higher was the level of social workers' devotion, burnout, and dissatisfaction in the work places. The impact of implicit rules was powerful in a few areas of work. That is, social workers were required to do whatever things at hand rather than carrying out professional tasks only. Social workers were also asked to stay way beyond the closing hour. The explicit rules were dominant in the area concerned with social work ethics. Some strategies to substantiate social work practice were suggested on the basis of careful examination of the powerful implicit rules.

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A Study on Level of Company-Consumer Identification on Company Rumor Impact and Effectiveness of Refutation countered the effect of the difference (기업-소비자 동일시 수준에 따른 기업루머에 대한 반박효과의 차이)

  • Choi, Tae-Ho;Hwang, Ji-MIn;Oh, Dae-Yang
    • Management & Information Systems Review
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    • v.31 no.4
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    • pp.261-286
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    • 2012
  • Rumors are widely prevalent in marketplace and It can be problematic and dangerous for the company's reputation and damages their image. Recently, many companies are given trouble by rumors. As getting invigorates the social media, there is high possibility to shape the vicious rumors without any confirmation whether information is true or not. It affects the companies' reputation and trust they have built for long time, also sales drop off. Despite numerous denials, the rumor persisted, keeping occur again and again all the times. Refutation purposes to decrease levels of belief in a rumor. First, establish Study 1 that a variation in identification influences the impact of a rumor on individuals' beliefs. Furthermore, we analyze the effectiveness of a refutation under varying degree of one's level of identification with the rumor object. According to research result, the response pattern of identification and disidentificaion consumers are very different. Disidentifiers, who engaged in systematic processing, believed the rumor less only when the refutation contained strong arguments. Identifiers, processing heuristically, remained unbelieving in the rumor. Study found that identification is an important moderator of consumer response to negative rumors. These defensive processes alleviate the bad influence of that information, and also can reduce the likelihood of attitude degradation.

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