• Title/Summary/Keyword: Cumulative Risk

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A Study on the Selection of Target Ship for the Protection of Submarine Power Cable (해저 동력케이블 보호를 위한 대상 선박 선정에 관한 연구)

  • Lee, Yun-sok;Kim, Seungyeon;Yu, Yungung;Yun, Gwi-ho
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.6
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    • pp.662-669
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    • 2018
  • Recently, the installation of submarine power cables is under consideration due to the increase of electric power usage and the development of the offshore wind farm in island areas, including Jeju. In order to protect power cables installed on the seabed, it is necessary to calculate the burial depth based on the characteristics of anchoring, dragging and fishing, etc. However, there is no design standard related to the size of target ships to protect the cables in Korea. In this study, we analyzed the design standards for the protection of domestic submarine pipelines similar to submarine cables, and developed the risk matrix based on the classification by emergency anchoring considering the installation environment, then designed the size of target ships according to the cumulative function scale by ship size sailing through the sea concerned. Also, we linked marine accident conditions, such as anchoring, dragging, etc. and the environmental conditions such as current, sea-area depth of installation etc. to the criteria of the protection of submarine cable, and examined the size of specific target ships by dividing the operating environment of ships into harbor, coastal and short sea. To confirm the adequacy and availability of the size of target ships, we verified this result by applying to No. 3 submarine power cables, which is to be installed in the section from Wando to Jeju Island. This result is expected to influence in the development of a protection system for submarine cables and pipelines as well as the selection of anchor weight according to the determination of burial depth.

Mitigation of Methane Emission and Energy Recycling in Animal Agricultural Systems

  • Takahashi, J.;Mwenya, B.;Santoso, B.;Sar, C.;Umetsu, K.;Kishimoto, T.;Nishizaki, K.;Kimura, K.;Hamamoto, O.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.8
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    • pp.1199-1208
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    • 2005
  • Abatement of greenhouse gas emitted from ruminants and promotion of biogas energy from animal effluent were comprehensively examined in each anaerobic fermentation reactor and animal experiments. Moreover, the energy conversion efficiency of biomass energy to power generation were evaluated with a gas engine generator or proton exchange membrane fuel cell (PEMFC). To mitigate safely rumen methanogenesis with nutritional manipulation the suppressing effects of some strains of lactic acid bacteria and yeast, bacteriocin, $\beta$1-4 galactooligosaccharide, plant extracts (Yucca schidigera and Quillaja saponarea), L-cysteine and/or nitrate on rumen methane emission were compared with antibiotics. For in vitro trials, cumulative methane production was evaluated using the continuous fermented gas qualification system inoculated with the strained rumen fluid from rumen fistulated Holstein cows. For in vivo, four sequential ventilated head cages equipped with a fully automated gas analyzing system were used to examine the manipulating effects of $\beta$1-4 galactooligosaccharide, lactic acid bacteria (Leuconostoc mesenteroides subsp. mesenteroides), yeast (Trichosporon serticeum), nisin and Yucca schidigera and/or nitrate on rumen methanogenesis. Furthermore, biogas energy recycled from animal effluent was evaluated with anaerobic bioreactors. Utilization of recycled energy as fuel for a co-generator and fuel cell was tested in the thermophilic biogas plant system. From the results of in vitro and in vivo trials, nitrate was shown to be a strong methane suppressor, although nitrate per se is hazardous. L-cysteine could remove this risk. $\beta$1-4 galactooligosaccharide, Candida kefyr, nisin, Yucca schidigera and Quillaja saponarea are thought to possibly control methanogenesis in the rumen. It is possible to simulate the available energy recycled through animal effluent from feed energy resources by making total energy balance sheets of the process from feed energy to recycled energy.

Dose Assessment of the Eye of the Operator in the Field of Angiography and Interventional Radiography (혈관조영 및 중재적 시술 분야 내 종사자의 눈에 대한 선량평가)

  • Kim, Jung-hoon;Cho, Yong-In
    • Journal of the Korean Society of Radiology
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    • v.12 no.2
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    • pp.209-216
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    • 2018
  • In the field of angiography and interventional radiology, it is said that the risk of radiation exposure to the eyes is high due to the characteristics of work, but currently divided dose assessment and management are not carried out in reality. Therefore, in this study, in order to evaluate the dose of the operator in the surgical environment and to analyze the shields, firstly, we selected the point where the operator is mainly located, evaluated the exposure dose of the eye after attaching the pocket dosimeter to the lateral angle point of the head and neck phantom, and evaluate shielding effect when wearing lead glasses that is currently commercialized. Secondly, we evaluated the tendency of the exposure dose of the eye and the shielding effect through simulation in the same geometric structure as the actual measurement. As a result, in the case of measurement using a dosimeter, the cumulative dose increased with the increase of the fluoroscopic time, and the tendency was different according to the position of the operator. Simulation results show that the dose distribution of the eye lens in the mathematical phantom is about 1.1 ~ 1.3 times higher than that of the cornea. Also, The protective effect of the lead glasses showed a shielding effect of at least 3.7 ~ 21.4% in each eye.

Synergistic and Antagonistic Interactions for Pesticide mixtures to Honeybee Larvae Toxicity (농약 혼용에 따른 꿀벌유충 독성의 상승 및 상쇄 영향)

  • Paik, Min Kyoung;Im, Jeong Taek;Chon, Kyongmi;Park, Kyung-Hun;Choi, Yong-Soo;Lee, Myeong-Lyeol;Bae, Chul-Han;Kim, Jin-Ho;Moon, Byeong Chul
    • Korean Journal of Environmental Agriculture
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    • v.35 no.4
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    • pp.241-246
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    • 2016
  • BACKGROUND: Recently, the widespread distribution of pesticides in the hive has been of concern about pesticide exposure on honeybee (Apis mellifera L.) health. Larval toxicity was adapted to assess the synergistic and antagonistic interaction of cumulative mortality to the honeybee larvae of the four most common pesticides detected in pollen. METHODS AND RESULTS: Acetamiprid($3.0{\mu}l/L$), chlorothalonil ($803.0{\mu}l/L$), coumaphos ($128.0{\mu}l/L$), and tau-fluvalinate ($123.0{\mu}l/L$) were tested in combination; binary, ternary and four component mixture. Larvae were exposed to four pesticides mixed in diet at the average levels detected in pollen. As a result, synthetic toxicity was observed in the binary mixture of acetamiprid with coumaphos. The binary and ternary component mixtures of tested pesticides have mostly demonstrated additive effect in larval bees. The significant antagonistic effects were found in four parings of mixtures including chlorothalonil added to acetamiprid/tau-fluvalinate or acetamiprid/coumaphos/tau-fluvalinate, and tau-fluvalinate added to acetamiprid/chlorothalonil or acetamiprid/coumaphos/chlorothalonil. CONCLUSION: Interactions between combinations of four pesticides showed mostly additive or antagonistic effects in larval bees. Therefore, predicting the larval mortality of pesticides mixtures on the basis of the results of single pesticide may actually overestimate the risk. We suggest that pesticide mixture in pollen be evaluated by adding their toxicity together for complete data on interactions.

Cardiac valve replacement: a 7-year long-term evaluation (심장조직판막치환: 7 년간의 술후 장기성)

  • Lee, Sang-Ho;Seong, Sang-Hyeon;Seo, Gyeong-Pil
    • Journal of Chest Surgery
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    • v.16 no.4
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    • pp.602-614
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    • 1983
  • Six hundred fourteen consecutive cases of bioprosthetic cardiac valve replacement performed during the period from March 1976 through December 1982 were reviewed. A total of 748 tissue valves [534 Ionescu-Shiley valves, 144 Hancock valves, 46 Angell-Shiley, and 24 Carpentier-Edwards] were implanted in 610 patients. Of these, 477 had single valve replacements [403 mitral, 60 aortic, and 14 tricuspid] including three REDO MVR and one REDO AVR. The remaining 129 had double valve replacements [95 AVR and MVR and 34 MVR and TVR] and 8 had triple valve replacement.592 cases were evaluated. Overall early mortality rate [within 30 days of operation] was 7.1% [6.2% in single valve replacement, 10.2% in double valve replacement, and 16.7% in triple valve replacement]. Leading causes of mortality were low cardiac output or myocardial failure and ventricular arrhythmias. The follow-up period was from one month to 7 years with a cumulative follow-up of 906.6 patient-years [mean 1.53 years]. The late mortality was 1.6%, 3.9%, 0%, 2.6%, 6.6% and 2.0% per patient-year for MVR, AVR, TVR or triple valve replacement, AVR+MVR, MVR+TVR and total, respectively. Actuarial analysis of late results including early mortalities indicates an expected survival rate of 87.6+1.8% at 3 years and 85.92.4% at 7 years for all cases. We also analyzed actuarial survival rate between groups of each valve replacement [AVR, TVR, Double valve, and Triple valve] and the tissue valve groups in MVR. We experienced 7 cases [0.77% per patient-year] of confirmed endocarditis, two of which were fatal. Valve failure-free rates calculated according to the confirmed cases were 97.5% at 4 years, 87.5% at 7 years, and 88.3% at 6 years for Ionescu-Shiley, Hancock and Angell-Shiley valves, respectively. The occurrence rate of thromboembolism was 2.0% per patient-year in total cases, although almost all the patients were given anticoagulant therapy for one year. The occurring rate in MVR was 1.5% and 2.7% per patient-year for Ionescu-Shiley and Hancock valve groups, respectively. The difference in actuarial rate free from thromboemboli between Ionescu-Shiley and Hancock groups was statistically significant [P value less than 0.001]. Thromboembolic events beyond the period of anticoagulation therapy mainly occurred in patients with atrial fibrillation. The actuarial thromboemboli free survival was 95.71.4% at 3 years and 80.17.3% at 7 years. The incidence of hemorrhagic complications was 1.2% per patient-year [fatality 0.55% per patient-year] for anticoagulated patients. Although our clinical data favorably compares with results from other reports, our results suggest that anticoagulant therapy be given on a short-term basis or not at all to hemodynamically stable patients. Long-term therapy with antiplatelet drugs is probably inevitable with patients who have thromboembolic risk factors [such as atrial fibrillation].

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A Study on the University Student's Consciousness about Sex and AIDS (대학생의 성 및 AIDS에 관한 의식 연구)

  • 강병우
    • Korean Journal of Health Education and Promotion
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    • v.11 no.1
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    • pp.43-56
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    • 1994
  • Although the officially confirmed incidence of the acquired immune deficiency syndrome(AIDS) has remained low thus far in Korea, the progression of the pandemic has been rapid, concerned about an eventual increase in transmission. Until a vaccine or cure is found, public information and education remain an important weapon against AIDS. For the year 2000, the current WHO projection is that there will be a cumulative total of 40 million HIV infections in man, woman and children, of which more than 90% will be in the developing countries. The incerased mortality among adults and children has raised concerns that AIDS may become so devastaing as to reverse positive population growth rates and wipe out entire population. In order to plan for the rising incidence of patient with AIDS, an assessment of AIDS-related cognition and behavior, attitude of the recognized high-risk groups is necessary. Considering that undergraduates have sexuality active and more oriented toward sexual concerns than other ages. Adolescents today are more sexually involved than in the past: The media, including films, music, and television, reinforce sexual concerns by preseating images of highly sexual adolescents. Incidence of both petting and sexual intercourse in higher and occurs at earlier ages, they are important reservoir of AIDS infection. Hence, it has become important to emymerats and describe the knowledge, attitude and behavior of them, I want.. This information will eventually guide the direction of change in public policies and education programs to meet the challenges of AIDS. The objective of this study were to identity Knowledge, Attitude, Experience of Sex and AIDS in Korea. The data were collected by survey at Korean Federation for AIDS Affairs, INC. and J university, K junior college. After October in 1993, surveyed with 507 student during their's college days in Seoul. The questionnaire was designed to provide information on sex and AIDS-related knowledge and attitudes and experience. AIDS-related knowledge was measured by using 26 questions on mode of transmission and AIDS-related attitudes were measured by 7 questions, AIDS-related experience was measured by 5 questions. There were the main dependent variables in our study, In conclusion, students during their university day need to develop AIDS-preventive education programs. Clearly, the many AIDS-prevention educational effort need to be guided by well trained health agents. Financial supports from all sectors (i.e., public and private) of our society are required to achieve that end. Further researches on AIDS-related Knowledge and Attitude and behaviors of undergraduates are needed for the development of comprehensive AIDS prevention programs.

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An Empirical Study on Trading Techniques Using VPIN and High Frequency Data (VPIN과 고빈도 자료를 활용한 거래기법에 관한 실증연구)

  • Jung, Dae-Sung;Park, Jong-Hae
    • Management & Information Systems Review
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    • v.38 no.4
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    • pp.79-93
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    • 2019
  • This study analyzed the information effect of KOSPI200 market and KOSPI200 futures market and volume synchronized probability of informed trading (VPIN). The data period is 760 days from July 8, 2015 to August 9, 2018, and the intraday trading data is used based on the trading period of the KOSPI 200 Index. The findings of the empirical analysis are as follows. First, as a result of regression analysis of the same parallax, when the level of VPIN is high, the return and volatility of KOSPI200 are high. Second, the KOSPI200 returns before and after the VPIN measurement and the return of the KOSPI200 future had a positive relationship with the VPIN. The cumulative returns of KOSPI200 futures were positive for about 15 minutes.Finally, we find that portfolios with high levels of VPIN showed high KOSPI200 and KOSPI200 futures return. These results confirmed the applicability of VPIN as a trading strategy index. The above results suggest that KOSPI200 and KOSPI200 futures markets will be able to explore volatility and price changes, and also be useful indicators of financial market risk.

Systematic Review : Comparative Safety and Efficacy of Mono- and Combination Therapy of Anti-hypertensive Agents Acting on the Renin-Angiotensin System (레닌-안지오텐신계에 작용하는 항고혈압 약제의 단독요법과 병용요법의 안전성 및 유효성에 대한 체계적 문헌고찰)

  • Choi, Kyung-Eob;Kim, Hyun-Kyung
    • Korean Journal of Clinical Pharmacy
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    • v.21 no.4
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    • pp.364-375
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    • 2011
  • Given that single blockade with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) can achieve only partial and undurable suppression of the Renin Angiotensin System (RAS), it has been hypothesized that dual blockage would be more beneficial in the management of blood pressure (BP) reduction and prevention of progressive chronic kidney disease (CKD) than either agent alone. Thus, it has been suggested that the combination of an ACEI and an ARB might provide renal benefits to hypertensive patients over and above BP reduction. However, this might also expose patients to additive or synergistic side effects. We attempted to conduct a systematic review to evaluate the benefits and harms of combination therapy in hypertensive patients with or without kidney diseases. MEDLINE and KoreaMed were searched for relevant randomized clinical trials in adult hypertensive patients with or without diabetes (restricted to 1997, limited to trials published in English). Results were summarized using the random-effects model, and between-studies heterogeneity was estimated with $I^2$. A final analysis of ten trials (23,928 patients) revealed that the combination of an ACEI and an ARB reduced blood pressure (SBP/DBP) by 3.95/2.02 mmHg (95% confidence interval [CI], -4.38 to -3.53/-2.33 to -1.71) compared with ACEI monotherapy, and 2.83/2.64 mmHg (95% CI, -3.25 to -2.41/-4.95 to -0.33) compared with ARB monotherapy. Eight trials (391 patients) demonstrated a significant reduction in 24h-proteinuria (weighted mean difference, 0.16 g/day, 95% CI, -0.26-0.05), but they did not translate into an improvement in GFR. Tests for heterogeneity showed no difference in effect among the studies. The combination therapy reduced proteinuria by 30% (95% CI, 23% to 37%) and 39% (95% CI, 31% to 48%) compared with ACEI monotherapy and ARB monotherapy, respectively. However, in patients who had proteinuria more than 0.5 g/day, the combination therapy failed to show significant reduction in urinary protein excretion. The current cumulative evidence suggests that diabetic patients with proteinuria on dual RAS blockade have an increase risk of adverse events such as hyperkalemia, hypotension, and so on, compared with ACEI or ARB alone. It is, therefore, proposed that the combination therapy should not be routinely used for the treatment of hypertension with or without compelling indications.

Optimal Seismic Rehabilitation of Structures Using Probabilistic Seismic Demand Model (확률적 지진요구모델을 이용한 구조물의 최적 내진보강)

  • Park, Joo-Nam;Choi, Eun-Soo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.3
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    • pp.1-10
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    • 2008
  • The seismic performance of a structure designed without consideration of seismic loading can be effectively enhanced through seismic rehabilitation. The appropriate level of rehabilitation should be determined based on the decision criteria that minimize the anticipated earthquake-related losses. To estimate the anticipated losses, seismic risk analysis should be performed considering the probabilistic characteristics of the hazard and the structural damage. This study presents the decision procedure in which the probabilistic seismic demand model is utilized for the effective estimation and minimization of the total seismic losses through seismic rehabilitation. The probability density function and the cumulative distribution function of the structural damage for a specified time period are established in a closed form, and are combined with the loss functions to derive the expected seismic loss. The procedure presented in this study could be effectively used for making decisions on the seismic rehabilitation of structural systems.

A Study on the Establishment of Quantitative Standards of Landslides Vulnerability by Climate Change (기후변화에 따른 산사태 취약성의 정량적 평가기준 설정 연구)

  • Lee, Dong-Kun;Kim, Hogul;Seo, Changwan;Song, Changkeun;Yu, Jeong Ah;Park, Chan
    • Journal of Climate Change Research
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    • v.4 no.2
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    • pp.95-104
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    • 2013
  • Average cumulative precipitation in summer have increased by 350 mm compared with 1980s. As precipitation is expected to increase, the risk of landslides by heavy rainfall also is expected to rise. Therefore, establishment of adaptation plan for landslides is urgently needed. In 2011, Korea Ministry of Environment(KME) conducted vulnerability assessment to support establishment of adaptation plan for local governments. However, the result of vulnerability assessment had three limitations. First, KME didn't use standard scenario of Korea Meteorological Administration(KMA). Second, They conducted same standardization method for all variables. Third, They derived relative vulnerability which is not quantitative. The purpose of this study is to improve the limitations of existing vulnerability assessment and identify quantitative criteria to ensure scientific reliability. To achieve this purpose, we carried out three ways of advancement. First, application of new climate scenario, which is RCP 8.5 from KMA. Second, improvement of variables of vulnerability assessment. Third, derivation of quantitative criteria of vulnerability. The findings can support establishment of adaptation plan for local governments more effectively.