• Title/Summary/Keyword: Failure life

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Effect of Probability Distribution of Coefficient of Consolidation on Probabilistic Analysis of Consolidation in Heterogeneous Soil (비균질 지반에서 압밀계수의 확률분포가 압밀의 확률론적 해석에 미치는 영향)

  • Bong, Tae-Ho;Heo, Joon;Son, Young-Hwan
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.3
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    • pp.63-70
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    • 2018
  • In this study, a simple probabilistic approach using equivalent coefficient of consolidation ($c_e$) was proposed to consider the spatial variability of coefficient of vertical consolidation ($c_v$), and the effect of the probability distribution of coefficient of consolidation on degree of consolidation in heterogeneous soil was investigated. The statistical characteristics of consolidation coefficient were estimated from 1,226 field data, and four probability distributions (Normal, Log-normal, Gamma, and Weibull) were applied to consider the effect of probability distribution. The random fields of coefficient of consolidation were generated based on Karhunen-Loeve expansion. Then, the equivalent coefficient of consolidation was calculated from the random field and used as the input value of consolidation analysis. As a result, the probabilistic analysis can be performed effectively by separating random field and numerical analysis, and probabilistic analysis was performed using a Latin hypercube Monte Carlo simulation. The results showed that the statistical properties of $c_e$ were changed by the probability distribution and spatial variability of $c_v$, and the probability distribution of $c_v$ has considerable effects on the probabilistic results. There was a large difference of failure probability depend on the probability distribution when the autocorrelation distance was small (i.e., highly heterogeneous soil). Therefore, the selection of a suitable probability distribution of $c_v$ is very important for reliable probabilistic analysis of consolidation.

Roles of Conceptus Secretory Proteins in Establishment and Maintenance of Pregnancy in Ruminants

  • Bazer, Fuller W.;Song, Gwon-Hwa;Thatcher, William W.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.1
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    • pp.1-16
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    • 2012
  • Reproduction in ruminant species is a highly complex biological process requiring a dialogue between the developing conceptus (embryo-fetus and associated placental membranes) and maternal uterus which must be established during the peri-implantation period for pregnancy recognition signaling and regulation of gene expression by uterine epithelial and stromal cells. The uterus provide a microenvironment in which molecules secreted by uterine epithelia and transported into the uterine lumen represent histotroph, also known as the secretome, that are required for growth and development of the conceptus and receptivity of the uterus to implantation by the elongating conceptus. Pregnancy recognition signaling as related to sustaining the functional lifespan of the corpora lutea, is required to sustain the functional life-span of corpora lutea for production of progesterone which is essential for uterine functions supportive of implantation and placentation required for successful outcomes of pregnancy. It is within the peri-implantation period that most embryonic deaths occur in ruminants due to deficiencies attributed to uterine functions or failure of the conceptus to develop appropriately, signal pregnancy recognition and/or undergo implantation and placentation. The endocrine status of the pregnant ruminant and her nutritional status are critical for successful establishment and maintenance of pregnancy. The challenge is to understand the complexity of key mechanisms that are characteristic of successful reproduction in humans and animals and to use that knowledge to enhance fertility and reproductive health of ruminant species in livestock enterprises.

Transcatheter Closure of a Residual Shunt after Surgical Repair of Traumatic Ventricular Septal Defect (외상성 심실중격결손 수술 후 잔존하는 심실중격결손에 대한 중재적 심도자술을 이용한 폐쇄)

  • Jeong, Hee Jeong;Lim, Han Hyuk;Yu, Jae Hyun;Lee, Jae Hwan;Kil, Hong Ryang
    • Clinical and Experimental Pediatrics
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    • v.48 no.10
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    • pp.1143-1143
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    • 2005
  • The traumatic ventricular septal defect (VSD) is a rare but potentially life threatening complication of chest wall injury. The traumatic VSD occurs in up to 4.5% of penetrating cardiac trauma. Most of the patients are usually operated on because of heart failure and/or significant left-to-right shunt. The feasibility of surgical repair under cardiopulmonary bypass may be affected by coexisting pulmonary, cerebral or other vascular injuries. Transcatheter closure of VSD is being considered as an alternative therapeutic modality to surgery in order to avoid the potential risk of cardiopulmonary bypass. We report a patient who underwent a successful transcatheter closure of VSD with an $Amplatzer^{(R)}$ VSD occluder. The patient had a residual VSD with significant left-to-right shunt after surgical repair of post-traumatic VSD using cardiopulmonary bypass.

The optimal model of reperfusion injury in vitro using H9c2 transformed cardiac myoblasts

  • Son, Euncheol;Lee, Dongju;Woo, Chul-Woong;Kim, Young-Hoon
    • The Korean Journal of Physiology and Pharmacology
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    • v.24 no.2
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    • pp.173-183
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    • 2020
  • An in vitro model for ischemia/reperfusion injury has not been well-established. We hypothesized that this failure may be caused by serum deprivation, the use of glutamine-containing media, and absence of acidosis. Cell viability of H9c2 cells was significantly decreased by serum deprivation. In this condition, reperfusion damage was not observed even after simulating severe ischemia. However, when cells were cultured under 10% dialyzed FBS, cell viability was less affected compared to cells cultured under serum deprivation and reperfusion damage was observed after hypoxia for 24 h. Reperfusion damage after glucose or glutamine deprivation under hypoxia was not significantly different from that after hypoxia only. However, with both glucose and glutamine deprivation, reperfusion damage was significantly increased. After hypoxia with lactic acidosis, reperfusion damage was comparable with that after hypoxia with glucose and glutamine deprivation. Although high-passage H9c2 cells were more resistant to reperfusion damage than low-passage cells, reperfusion damage was observed especially after hypoxia and acidosis with glucose and glutamine deprivation. Cell death induced by reperfusion after hypoxia with acidosis was not prevented by apoptosis, autophagy, or necroptosis inhibitors, but significantly decreased by ferrostatin-1, a ferroptosis inhibitor, and deferoxamine, an iron chelator. These data suggested that in our SIR model, cell death due to reperfusion injury is likely to occur via ferroptosis, which is related with ischemia/reperfusion-induced cell death in vivo. In conclusion, we established an optimal reperfusion injury model, in which ferroptotic cell death occurred by hypoxia and acidosis with or without glucose/glutamine deprivation under 10% dialyzed FBS.

T&E Process for Safety-Critical CNS/ATM Systems (안전필수항행시스템의 시험평가 프로세스)

  • Kang, Ja-Young;Kim, Mu-Geun;Kim, Young-Hoon;Lim, In-Kyu
    • Journal of Advanced Navigation Technology
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    • v.21 no.1
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    • pp.50-57
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    • 2017
  • Recently, safety-critical aviation system development programs promoted domestically have been terminated in the middle stage or they have not been put to practical use at the final stage. The program failure may be caused by various factors, but this study focused on imperfect test and evaluation(T&E) procedures. In general, T&E process of a safety-critical system must be distributed throughout the entire life-cycle of the system, have a continuity in phases, and can be implemented in a variety of ways depending on the maturity of the system development and acquisition strategy. This paper aims to present a new strategy by analyzing the domestic and overseas T&E processes to reduce the risk of domestic safety-critical CNS/ATM system development program and increase the success rate of program. First, we discuss the verification and validation techniques for safety-critical systems, analyze the T&E procedures of advanced institutes and the domestic situation, and then compare the domestic and overseas T&E processes to complement the imperfect testing procedure.

An Investigation of Chemyon on Consumption Behavior of Asian and Western Consumers: Cross-Cultural Comparative Approach (체면 관점에서 본 동서양 소비자들의 소비행동에 관한 고찰: 비교문화 접근방법)

  • KIM, Young-Doo
    • The Journal of Industrial Distribution & Business
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    • v.10 no.5
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    • pp.37-47
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    • 2019
  • Purpose - It is well known that chemyon, referred to by Westerners as face, naturally penetrates the daily life of Asians and influences their cognition, emotion, and behavior. Studies related to chemyon have been conducted in marketing and consumer behavior fields (e.g., luxury products or brands, service failure and recovery, brand preferences, consumer decision making, wedding ceremony, gift giving). A bulk of studies demonstrate that chemyon influences consumption behavior in Asian consumers. Although chemyon significantly influences consumption behavior of Asian consumers, it is also a cultural phenomenon that is not completely explained within the Western viewpoint. Whereas a number of researchers have approached cross-cultural studies of Asian and Western consumers, a limited number of studies have examined it from the perspective of chemyom. The purpose of this study is to compare the phenomenon that chemyon (face) not only affects the consumption behavior of Asia and the West universally (pan-culturally), but also distinctively (culture-specifically). That is, the purpose of this study is to describe that chemyon (face) is not only a culture-specific phenomenon but also a universal phenomenon in the consumption behavior of Asian and Western consumers, even though the extent that chemyon (face) impacts consumption behavior is differentiated. This study aims to understand commonalities and differences between Asian and Western consumption behavior in terms of chemyon (face), and to suggest how to enhance marketing effectiveness in a global market based on understanding the consumption behavior of Asia and the West. Research design, data, and methodology - Using systematic literature review and meta-analysis, this study investigates consumption behavior of Asian and Western consumers from the perspective of chemyon (face). Systematic literature review was used to compare face (chemyon) consumption of Western consumers with that of Asian consumers. To verify systematic literature review, meta-analysis was also accomplished. Results - First, the influence of face (chemyon) on consumption behavior is observed in Western consumers as well as Asian consumers. Second, Asian consumers are more influenced by face (chemyon) than Western consumers. Conclusions - Overall, chemyon (face) can affect the consumption behavior of Asians as well as the consumption behavior of Westerners.

The Public Choice Analysis of Korean Mobile Telecom Policy (이동통신정책의 공공선택 분석)

  • Shin, Jin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.3
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    • pp.493-499
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    • 2015
  • In Korea mobile phone subscribers exceeded 1 million people in 1995, and ten million people in 1998. Prevalence of the mobile phone increased dramatically over 110% compared to the population. Almost every family members including children uses more than one mobile terminal. Mobile phone is obviously more necessary good than washer, vacuum cleaner and passenger car. Our daily life are conveniently positioned with mobile communication, but communication related costs including the price of the device and service charges become a big burden on the household. But the government does not seem to do the right role at the right time to prevent the market failure to maximize consumer welfare and social welfare through supporting fair competition. This principal-agent problem issues of mobile communication policies will be understood in perspective of public choice against joint use of the mobile communication network, number portability, separation of phone distribution and phone service, network neutrality, mobile phone subsidy since the early 1990s when mobile phone service was introduced in Korea.

Assessment of Geosynthetic Soilbag Method to Restore the Roadbed of Railway (철도노반 복구를 위한 토목섬유 Soilbag 공법의 적용성 평가)

  • Hwang, Seon-Keun;Koh, Tae-Hoon;Park, Sung-Hyun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.4 no.1 s.12
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    • pp.65-75
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    • 2004
  • Roadbed failure due to the natural disaster may bring out social and economic damage such as the loss of life and property, the consumption of time and cost for recovery, and the delay of logistics in railway In this study, the method using geosynthetic soilbag was applied to rehabilitation of the railway roadbed which was failed by disaster. The full scale tests with the simulated train loading were performed in order to evaluate the static and dynamic performance at the railway roadbed using geosynthetic soilbag. The results of these tests were compared with unreinforced and reinforced cases with geosynthetic soilbag, respectively The data gathered by various measurement devices from these full scale tests would be useful to evaluate and understand the roadbed with geosynthetic soilbag. In conclusion, geosynthetic soilbag was evaluated as a permanent restoration method to reinforce the roadbed of railway.

A study on how lifestyle and shampoo habits affect middle-aged men with seborrheic Scalp - especially office workers (30~50대 중장년층 남성의 생활과 샴푸 습관이 지루성 두피에 미치는 영향에 관한 연구 : 사무직 군무 종사자들을 중심으로)

  • Lee, Jong-Youl;You, Seon-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.12
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    • pp.701-707
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    • 2016
  • This study surveyed 150 men aged 30 to 50, a demographic which seborrheic dermatitis is common. The time of day one shampoos and recurrent fatigue were found to have a statistically significant impact on symptoms contributing to the main causes of seborrhea, including itchiness, excessive oil, acne, and redness on the scalp (p<0.01). Study results confirm lifestyle and shampoo habits, such as the frequent sense of fatigue, a routine work schedule, susceptibility to stress, the time of day one uses shampoo, and whether hair styling products are used, affects seborrheic scalp disease. This study found seborrheic scalp disease for office workers primarily resulted from shampoo habits, rashes were predominantly caused by a failure to rinse shampoo and dry hair completely, while secondary aggravating factors included irregular work schedules, recurrent tiredness, and chronic stress.

The Prognostic Factors That Influence Long-Term Survival in Acute Large Cerebral Infarction

  • Cho, Sung-Yun;Oh, Chang-Wan;Bae, Hee-Joon;Han, Moon-Ku;Park, Hyun;Bang, Jae-Seung
    • Journal of Korean Neurosurgical Society
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    • v.49 no.2
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    • pp.92-96
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    • 2011
  • Objective : We retrospectively evaluated the prognostic factors that can influence long-term survival in patients who suffered acute large cerebral infarction. Methods : Between June 2003 and October 2008, a total of 178 patients were diagnosed with a large cerebral infarction, and, among them, 122 patients were alive one month after the onset of stroke. We investigated the multiple factors that might have influenced the life expectancies of these 122 patients. Results : The mean age of the patients was $70{\pm}13.4$ years and the mean survival was $41.7{\pm}2.8$ months. The mean survival of the poor functional outcome group ($mRS{\geq}4$) was $33.9{\pm}3.3$ months, whereas that of the good functional outcome group ($mRS{\leq}3$) was $58.6{\pm}2.6$ months (p value=0.000). The mean survival of the older patients (270 years) was $29.7{\pm}3.4$ months, whereas that of the younger patients (<70 years) was much better as $58.9{\pm}3.2$ months (p value=0.000). Involvement of ACA or PCA territory in MCA infarction is also a poor prognostic factor (p value=0.021). But, other factors that are also known as significant predictors of poor survival (male gender, hypertension, heart failure, atrial fibrillation, diabetes mellitus, a previous history of stroke, smoking, and dyslipidemia) did not significantly influence the mean survival time in the current study. Conclusion : Age (older versus younger than 70 years old) and functional outcome at one month could be critical prognostic factors for survival after acute large cerebral infarction. Involvement of ACA or PCA territory is also an important poor prognostic factor in patients with MCA territorial infarction.