• Title/Summary/Keyword: Hazard increase

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Estimation of Hazard Function and its Associated Factors in Gastric Cancer Patients using Wavelet and Kernel Smoothing Methods

  • Ahmadi, Azadeh;Roudbari, Masoud;Gohari, Mahmood Reza;Hosseini, Bistoon
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5643-5646
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    • 2012
  • Background and Objectives: Increase of mortality rates of gastric cancer in Iran and the world in recent years reveal necessity of studies on this disease. Here, hazard function for gastric cancer patients was estimated using Wavelet and Kernel methods and some related factors were assessed. Materials and Methods: Ninety-five gastric cancer patients in Fayazbakhsh Hospital between 1996 and 2003 were studied. The effects of age of patients, gender, stage of disease and treatment method on patient's lifetime were assessed. For data analyses, survival analyses using Wavelet method and Log-rank test in R software were used. Results: Nearly 25.3% of patients were female. Fourteen percent had surgery treatment and the rest had treatment without surgery. Three fourths died and the rest were censored. Almost 9.5% of patients were in early stages of the disease, 53.7% in locally advance stage and 36.8% in metastatic stage. Hazard function estimation with the wavelet method showed significant difference for stages of disease (P<0.001) and did not reveal any significant difference for age, gender and treatment method. Conclusion: Only stage of disease had effects on hazard and most patients were diagnosed in late stages of disease, which is possibly one of the most reasons for high hazard rate and low survival. Therefore, it seems to be necessary a public education about symptoms of disease by media and regular tests and screening for early diagnosis.

A Study on Comparative Evaluation of Application of Software Reliability Model Dependent on Various Hazard Functions (다양한 위험함수에 의존한 소프트웨어 신뢰모형의 적용에 대한 비교 평가에 관한 연구)

  • Yang, Tae-Jin
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.11 no.6
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    • pp.800-806
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    • 2018
  • Software efficiency is the probability of failure free use in operating environments, and is the most fundamental factor affecting software system stability. The malfunction of the computer system used in the information technology field may cause a significant loss in the related industry. Therefore, in this study, we analyze the attributes of software reliability models that depend on various hazard functions based on finite fault NHPP model with software failure time data. The hazard function pattern of proposed model is constant for the Goel-Okumoto model, and the Minimax and Rayleigh models follow the incremental pattern, but the hazard function increase value of the Minimax model is smaller than that of the Rayleigh model and the Goel-Okumoto model. Also, the Minimax model was relatively efficient because the true value error of the mean value function m(t) and the mean square error (MSE) of the Minimax model were smaller than those of the Rayleigh and Goel-Okumoto models. The results of this study are expected to be useful for software developers as basic information about the hazard function.

Effect of Stormwater Runoff on Combined Sewer Overflows in Korea

  • Kim, Lee-Hyung;Kim, Il-Kyu;Lee, Young-Sin;Lim, Kyeong-Ho
    • Journal of the Korean Society of Hazard Mitigation
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    • v.7 no.4
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    • pp.107-113
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    • 2007
  • The Kuem-River, one of the largest rivers in Korea, is the primary water source for more than 4 million people in Kongju city and surrounding area. To study the effect of stormwater runoff to CSOs, twelve monitoring sites were selected in two large cities (City of Kongju and City of Buyeo) near the Kuem-River. Monitoring was reformed by collecting grab samples, measuring flow rates during dry and wet seasons during over two rainy seasons. Generally the flow rate of wastewater in combined sewers was rapidly decreased after 23:00 P.M. and gradually increased from 06:30 A.M. in all sites during the dry season. The concentrations of pollutant increase approximately 5 to 7 fold for TSS and 1.5 to 2.5 fold for BOD during the rainy season. Monitoring and statistical analysis show that the groundwater contributes on sewage volume increase (average 25-45% more) during dry periods and the stormwater runoff contributes approximately 51-72% increase during rainy periods. Generally the concentrations of combined sewage were more polluted during the first flush period than after the first flush during a storm event.

Did Anti-dumping Duties Really Restrict Import?: Empirical Evidence from the US, the EU, China, and India

  • Choi, Nakgyoon
    • East Asian Economic Review
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    • v.21 no.1
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    • pp.3-27
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    • 2017
  • This paper studied the effects of anti-dumping measures on the imports to investigate whether the trade restriction effect of an anti-dumping duty is dominant. Our results indicate that a 1% increase in the anti-dumping duties decreases the import of the targeted product by about 0.43~0.51%. The actual statistics, however, show that the total import of the targeted products increased by about 30 percent while an anti-dumping duty was in force. That indicates that an anti-dumping duty is just a temporary import relief. This paper also investigated whether an anti-dumping duty is terminated in the case that the injury would not be likely to continue or recur if the duty were removed. The hazards model estimates show that increase in market share, MFN tariff rate, and dumping margin decrease the hazard of termination of an anti-dumping duty, but the increase in value added increases the hazard of termination. Generally speaking, this result indicates that the WTO member countries have regulated the overuse of an anti-dumping measure. The findings of this paper show that there is a country- and industry-wise heterogeneous characteristic in the effect as well as termination of an anti-dumping duty.

Analysis of Heavy Rain Hazard Risk Based on Local Heavy Rain Characteristics and Hazard Impact (지역 호우특성과 재해영향을 고려한 호우재해위험도 분석)

  • Yoon, Jun-Seong;Koh, June-Hwan
    • Journal of Cadastre & Land InformatiX
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    • v.47 no.1
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    • pp.37-51
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    • 2017
  • Despite the improvement in accuracy of heavy rain forecasting, socioeconomic costs due to heavy rain hazards continue to increase. This is due to a lack of understanding of the effects of weather. In this study, the risk of heavy rain hazard was analyzed using the concepts of hazard, vulnerability, and exposure, which are key concepts of impact forecast presented by WMO. The potential impacts were constructed by the exposure and vulnerability variables, and the hazard index was calculated by selecting three variables according to the criteria of heavy rain warning. Weights of the potential impact index were calculated by using PCA and hazard index was calculated by applying the same weight. Correlation analysis between the potential impact index and damages showed a high correlation and it was confirmed that the potential impact index appropriately reflects the actual damage pattern. The heavy rain hazard risk was estimated by using the risk matrix consisting of the heavy rain potential impact index and the hazard index. This study provides a basis for the impacts analysis study for weather warning with spatial/temporal variation and it can be used as a useful data to establish the local heavy rain hazard prevention measures.

Degradation of the Herbicide Butachlor by Laboratory-synthesized Nanoscale $Fe^0$ in Batch Experiments

  • Kim, Hyang-Yeon;Kim, In-Kyung;Han, Tae-Ho;Shim, Jae-Han;Kim, In-Seon
    • Journal of Applied Biological Chemistry
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    • v.49 no.3
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    • pp.101-105
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    • 2006
  • Degradation of the herbicide butachlor was investigated using laboratory-synthesized zerovalent iron ($Fe^0$). The synthesized zerovalent iron was determined to be nanoscale powder by scanning electron microscopic analysis. To investigate degradation of butachlor using the synthesized nanoscale zerovalent iron, time-course batch experiments were conducted by treating the solution of butachlor formulation with the iron. More than 90% degradation of butachlor was observed by iron treatment within 24 h. The synthesized nanoscale zerovalent iron showed an increase in particle aggregation in the batch tests. Green rust formation and a pH drop in solutions were observed, suggesting that the oxidation of the iron occurred. When the iron was extracted with dichloromethane, a negligible concentration was found in the extract, suggesting that butachlor did not bind to the iron particles. GC/MS analysis detected the dechlorinated product as a major degradation product of butachlor in the solutions. The data indicate that laboratory-synthesized zerovalent iron functioned as a reductant to remove electron-withdrawing chlorine, giving the dechlorinated product.

The Prediction of Landslide Hazard Areas Considering of Root Cohesion and Crown Density (뿌리점착력과 수관밀도를 적용한 토사재해 위험지역 예측)

  • Choi, Won-Il;Choi, Eun-Hwa;Suh, Jin-Won;Jeon, Seong-Kon
    • Journal of the Korean GEO-environmental Society
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    • v.17 no.6
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    • pp.13-21
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    • 2016
  • Since the landslide hazard areas prediction was analyzed by slope-angle and soil properties, regional characteristics is not taken. Therefore, in order to make more rational prediction, it is necessary to consider the characteristics of the region. Tree roots have been known to increase soil cohesion in landslide hazard areas and to vary the degrees depending on the tree type. In addition, a reasonable prediction of landslide hazard areas can be made by considering crown density based on crown distribution patterns of the area of interest. In this study, using the roots cohesion considering the crown density of the trees, which is in the landslides risk areas around Mt. Gwehwa in Sejong City, the landslides risk areas were predicted and compared with predicted results obtained by not considering root cohesion.

A Study on the Increase Installation of Sprinkler System in Residential Occupancies (주거용 스프링클러설비 설치의 확대에 관한 연구)

  • Jeong, Hyun-Gyu;Song, Yong-Sig;Lee, Jun-Suk;Cho, Won-Chol;Lee, Tae-Shik
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.522-525
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    • 2007
  • This study is for reduce the damage of human life and property occurred by a fire in the normal house and market according to increase rate of a fire. this is focused on the present domestic code about prevent a fire and sprinkler system in residential occupancies.

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Review about the Impacts from Volcanic Ash Fall (화산재 강하로부터의 영향 고찰)

  • Lee, Jeonghyun;Yun, Sung-Hyo
    • Korean Journal of Mineralogy and Petrology
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    • v.33 no.1
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    • pp.73-86
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    • 2020
  • The materials generating from volcanic eruption are volcanic gases, lavas and pyroclastic materials. Volcanic ash which has small-grain size (< 2 mm in diameter) can be moved easily and disperse widely, thus it may affect to communities across hundreds of square kilometers. The impacts from volcanic ash fall on people, structures, equipments, plants and livestock largely depend on ash thickness. According to increasing ash thickness, the intensity and area of damage may increase and affect significant damages not to human health but also to infrastructures. To reduce the impacts from volcanic ash fall, we have to establish the guidances about the nature and extent of the hazard and prepare the actions to increase abilities of communities to manage hazard. Although we don't have any experience caused by volcanic ash fall during and after volcanic eruption, we need to prepare the impacts of volcanic ash fall for future eruption in the areas surrounding Korea.

Risk perception and safety practice of paramedic students (응급구조학과 학생들의 교통 및 재난에 대한 위험인식 및 안전실천에 관한 연구)

  • Lee, Kyoung-Youl
    • The Korean Journal of Emergency Medical Services
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    • v.20 no.1
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    • pp.71-82
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    • 2016
  • Purpose: This research aimed to provide baseline data for undergraduate safety education by evaluating paramedic student risk perception and safety practice behavior regarding transport and disaster-related accidents. Methods: A total of 367 paramedic students at three different universities were surveyed using questionnaires. Risk perception questions about hazard, feeling of dread, and uncontrollable factors regarding seven items in transport and disasters were asked on a 7-point scale. Safety practice behavior consisted of 14 transport-related questions and 12 disaster-related questions in 4-point scale. All data were analyzed using SPSS Window 21.0. Results: Of 367 surveyed, 54.8% (201) were females, and 28.9% (106) were freshmen. In risk perception, 'drunk driving' in transport was the highest on average obtaining 6.49 points for hazard and 5.12 points for the feeling of dread. In disasters, 'war' recorded the highest average with 6.61 points for hazard and 5.71 points for the feeling of dread. In safety practice behavior regarding transport and disasters, a higher awareness of the need for safety education correlated with a significantly higher the rate of safety practice behavior (p <.001 respectively). Conclusion: The results indicate that undergraduates have inadequate perception of risk in emergencies. Safety education programs are needed to raise awareness of risks and to increase the safety practice rate.