Accident at Fukushima Dai-lchi Nuclear Power Plant--Lessons Learned for the Czech Republic

Accident at Fukushima Dai-ichi nuclear power plant significantly affected the nuclear industry at time when everybody was expecting the so called nuclear renaissance. There is no question that the accident has at least slowed it down. Research on this accident is taking place all over the world, in this paper, we present the findings of research on Fukushima nuclear power plant accident in relation to the Czech Republic. The paper focuses on the analysis of human performance during the accident. Lessons learned from the accident and main human errors are presented. First, the brief factors affecting the human performance are discussed. They are followed by the short description of activities on units 1-3. The key human errors in the accident mitigation are then identified. On unit 1, the fuel damage was probably impossible to prevent, however, on units 2 and 3, it could be probably prevented.

Delay Analysis Techniques Comparison

Many techniques have been used in the courts to demonstrate the criticalities of a delay event on the project schedule. At this time, there is no standard method to analyze a delay claim. This paper first introduced a fictional case study that has most types of delay and acceleration events that might be faced on a real project. The case study is applied to all current techniques of delay claims that have been identified from previous studies. The comparison uses the delay claim issues as criteria to evaluate all the delay claim techniques from the case study results. The case study result and discussion demonstrate that the Day-by-Day technique satisfies all the desired criteria while other techniques lack some.

Causation mechanism of coal miners' human errors in the perspective of life events

In order to effectively decrease the safety accidents caused by coal miners’human errors,this paper probes into the causality between human errors and life events,coping,psychological stress,psychological function,physiological function based on life events’vital influence on human errors,establishing causation mechanism model of coal miners’human errors in the perspective of life events by the researching method of structural equation.The research findings show that life events have significantly positive influence on human errors,with a influential effect value of 0.7945 and a influential effect path of‘‘life events—psychological stress—psychological function—physiological function—human errors’’and‘‘life events—psychological stress—physiological function—human errors’’.

The Combined Effect of Initial Error and Model Error on ENSO Prediction Uncertainty Generated by the Zebiak-Cane Model

Initial errors and model errors are the source of prediction errors. In this study, the authors compute the conditional nonlinear optimal perturbation （CNOP）-type initial errors and nonlinear forcing singular vector （NFSV）- type tendency errors of the Zebiak-Cane model with respect to El Nifio events and analyze their combined effect on the prediction errors for E1 Nino events. The CNOP- type initial error （NFSV-type tendency error） represents the initial errors （model errors） that have the largest effect on prediction uncertainties for E1 Nifio events under the perfect model （perfect initial conditions） scenario. How- ever, when the CNOP-type initial errors and the NFSV- type tendency errors are simultaneously considered in the model, the prediction errors caused by them are not am- plified as the authors expected. Specifically, the predic- tion errors caused by the combined mode of CNOP-type initial errors and NFSV-type tendency errors are a little larger than those caused by the NFSV-type tendency er- rors. This fact emphasizes a need to investigate the opti- mal combined mode of initial errors and tendency errors that cause the largest prediction error for E1 Nifio events.

Comparison of Two Earthquake Location Methods for Seismic Early Warning

In this paper,according to the Fujian Seismic Network earthquake catalog records,the T now method and the Four Stations Continuous Location method( hereinafter called FSCL)put forward by Jin Xing are inspected by using P-wave arrival information of the first four stations of each seismic event. Results show that for earthquakes within the network,both methods can obtain similar location results and location deviations are small for the majority of the events. For earthquakes outside the network,the location deviation may be amplified as the epicentral distance increases,owing to the seismic station distribution which spread toward the side of the epicenter and the small opening angle between seismic stations used for locating and epicenter. For the FSCL method,the impacts of the wave velocity on the location results may be significant for earthquakes outside the network.Thus,selecting a velocity model which is similar to the actual structure of the wave velocity will contribute to improving location results of earthquakes. The FSCL method can locate more seismic events than the T now method. It concludes that the T now method makes use of mistake information from some non-triggering stations in earthquake catalog,and some P-wave arrivals are not included in the earthquake catalog due to discontinuous records or unclear records of the seismic phase,which induces incorrect location.

一双胎底鞋

儿子要改建我的旧房,在清理杂物时,我在一个篓子下面翻出一双蒙满尘埃的胎底鞋。这双久违的鞋,勾起了我对往事的回忆。以前在乡下穿草鞋是常见的事,只因是稻草编成的,不耐磨而常误事。农村劳动强度大,常负重走远路,为此,我总想买一双价廉耐磨的鞋。

Using CMIP5 model outputs to investigate the initial errors that cause the “spring predictability barrier” for El Nio events

Most ocean-atmosphere coupled models have difficulty in predicting the E1 Nifio-Southern Oscillation （ENSO） when starting from the boreal spring season. However, the cause of this spring predictability barrier （SPB） phenomenon remains elusive. We investigated the spatial characteristics of optimal initial errors that cause a significant SPB for E1 Nifio events by using the monthly mean data of the pre-industrial （PI） control runs from several models in CMIP5 experiments. The results indicated that the SPB-related optimal initial errors often present an SST pattern with positive errors in the central-eastern equatorial Pa- cific, and a subsurface temperature pattern with positive errors in the upper layers of the eastern equatorial Pacific, and nega- tive errors in the lower layers of the western equatorial Pacific. The SPB-related optimal initial errors exhibit a typical La Ni- fia-like evolving mode, ultimately causing a large but negative prediction error of the Nifio-3.4 SST anomalies for El Nifio events. The negative prediction errors were found to originate from the lower layers of the western equatorial Pacific and then grow to be large in the eastern equatorial Pacific. It is therefore reasonable to suggest that the E1 Nifio predictions may be most sensitive to the initial errors of temperature in the subsurface layers of the western equatorial Pacific and the Nifio-3.4 region, thus possibly representing sensitive areas for adaptive observation. That is, if additional observations were to be preferentially deployed in these two regions, it might be possible to avoid large prediction errors for E1 Nifio and generate a better forecast than one based on additional observations targeted elsewhere. Moreover, we also confirmed that the SPB-related optimal initial errors bear a strong resemblance to the optimal precursory disturbance for E1 Nifio and La Nifia events. This indicated that im- provement of the observation network by additional observations in the identified sensitive areas would also be helpful in de- tecting the signals provided by the precursory disturbance, which may greatly improve the ENSO prediction skill.

The predictability of atmospheric and oceanic motions:Retrospect and prospects

This paper reviews the historic understanding of the predictability of atmospheric and oceanic motions, and interprets it in a general framework. On this basis, the existing challenges and unsolved problems in the study of the intrinsic predictability limit(IPL) of weather and climate events of different spatio-temporal scales are summarized. Emphasis is also placed on the structure of the initial error and model parameter errors as well as the associated targeting observation issue. Finally, the predictability of atmospheric and oceanic motion in the ensemble-probabilistic methods widely used in current operational forecasts are discussed.The necessity of considering IPLs in the framework of stochastic dynamic systems is also addressed.

Misdiagnosed coronary artery disease-acute aortic syndrome： A case report

It is estimated that 15% of traffic accidents cause trauma to large vessels. In about 70%-95% of cases, aortic rupture took place in the distal ligament of the left subclavian artery, whereas in the remaining cases rupture occurred in the ascending aorta above the aortic valve. Trauma to the aortic sinus and coronary arteries is rarely found in traffic accident victims. Therefore, coronary artery trauma is often misdiagnosed as coronary atherosclerotic heart disease. The present case is a 42 years old male who survived from a traffic accident. He presented with aortic sinus and left coronary artery trauma. He was misdiagnosed as having coronary atherosclerotic heart disease, and therefore wrongly given antiplatelet medicine, such as aspirin, in another hospital. Definite diagnosis was achieved in our hospital, and the patient underwent Bentall and mitral valve replacement, as well as tricuspid valvuloplasty. The aortic occlusion time during surgery was 47 min, and the total cardiopulmonary bypass time was 63 rain. After surgery, transthoracic echocardiography confirmed that all the artificial valves worked sufficiently. The patient felt good and symptoms such as asthma and decreased exercise tolerance disappeared. This case taught us that acute aortic syndrome cannot be ignored when patients present with pectoralgia; antiplatelet medication should not be given before definite diagnosis.

Analysis of false alarm for imaging space-based laser warning system

In view of the problem of false alarm in imaging space-based laser warning system, the effects of sunlight and lightning on the threaten laser detection and attack event determination are studied by analyzing and calculating the radiant energy density and space-time feature of imaging spot, respectively. The results show that the main false alarm resourses of space- based laser warning system are sunlight and lightning. The sunlight should exposure the detector directly in one ninth of the satfllite orbital period, and the imaging spot of sun is similar to the attack laser. The lightning imaging spot is similar to the illumination laser. About 1.4 lightning events can occur in the field of view （FOV） of the warning system per second. It could not discriminate spots of sun, lightning and threaten laser by the frame subtraction technology.