• Nuclear Engineering and Technology
• /
• v.56 no.4
• /
• pp.1501-1512
• /
• 2024

Plasma disruption in tokamak experiments is a challenging issue that causes damage to the device. Reliable prediction methods are needed, but the lack of full understanding of plasma disruption limits the effectiveness of physics-driven methods. Data-driven methods based on supervised learning are commonly used, and they rely on labelled training data. However, manual labelling of disruption precursors is a time-consuming and challenging task, as some precursors are difficult to accurately identify. The mainstream labelling methods assume that the precursor onset occurs at a fixed time before disruption, which leads to mislabeled samples and suboptimal prediction performance. In this paper, we present disruption prediction methods based on anomaly detection to address these issues, demonstrating good prediction performance on J-TEXT and EAST. By evaluating precursor onset times using different anomaly detection algorithms, it is found that labelling methods can be improved since the onset times of different shots are not necessarily the same. The study optimizes precursor labelling using the onset times inferred by the anomaly detection predictor and test the optimized labels on supervised learning disruption predictors. The results on J-TEXT and EAST show that the models trained on the optimized labels outperform those trained on fixed onset time labels.

• The Korean Journal of Air & Space Law and Policy
• /
• v.1
• /
• pp.47-85
• /
• 1989

The Fundamental purpose of the Warsaw Convention was to establish uniform rules applicable to international air transportation. The emphasis on the benefits of uniformity was considered important in the beginning and continues to be important to the present. If the desire for uniformity is indeed the mortar which holds the Warsaw system together then it should be possible to agree on a worldwide liability limit. This liability limit would not be so unreasonable, that it would be impossible for nations to adhere to it. It would preclude any national supplemental compensation plan or Montreal Agreement type of requirement in any jurisdiction. The differentiation of liability limits by national requirement seems to be what is occurring. There is a plethora of mandated limits and Montreal Agreement type 'voluntary' limits. It is becoming difficult to find more than a few major States where an unmodified Warsaw Convention or Hague Protocol limitation is still in effect. If this is the real world in the 1980's, then let the treaty so reflect it. Upon reviewing the Warsaw Convention, its history and the several attempts to amend it, strengths become apparent. Hijackings of international flights have given rise to a number of lawsuits by passengers to recover damages for injuries suffered. This comment is concerned with the liability of an airline for injuries to its passengers resulting from aviation terrorism. In addition, analysis is focused on current airline security measures, particularly the pre-boarding screening system, and the duty of air carriers to prevent weapons from penetrating that system. An airline has a duty to exercise a high degree of care to protect its passengers from the threat of aviation terrorism. This duty would seemingly require the airline to exercise a high degree of care to prevent any passenger from smuggling a weapon or explosive device aboard its aircraft. In the case an unarmed hijacker who boards having no instrument in his possession with which to promote the hoax, a plaintiff-passenger would be hard-pressed to show that the airline was negligent in screening the hijacker prior to boarding. In light of the airline's duty to exercise a high degree of care to provide for the safety of all the passengers on board, an acquiescene to a hijacker's demands on the part of the air carrier could constitute a breach of duty only when it is clearly shown that the carrier's employees knew or plainly should have known that the hijacker was unarmed. A finding of willful misconduct on the part of an air carrier, which is a prerequisite to imposing unlimited liability, remains a question to be determined by a jury using the definition or standard of willful misconduct prevailing in the jurisdiction of the forum court. Through the willful misconduct provision of the Warsaw Convention, air carrier face the possibility of unlimited liability for failure to implement proper preventive precautions against terrorist. Courts, therefore, should broadly construe the willful misconduct provision of the Warsaw Convention in order to find unlimited liability for passenger injuries whenever air carrier security precautions are lacking. In this way, the courts can help ensure air carrier safety and prevention against terrorist attack. Air carriers, therefore, would have an incentive to increase, impose and maintain security precautions designed to thwart such potential terrorist attacks as in the case of Korean Air Lines Flight No.858 incident having a tremendous impact on the civil aviation community. The crash of a commercial airliner, with the attending tragic loss of life and massive destruction of property, always gives rise to shock and indignation. The general opinion is that the legal system could be sufficient, provided that the political will is there to use and apply it effectively. All agreed that the main responsibility for security has to be borne by the governments. I would like to remind all passengers that every discovery of the human spirit may be used for opposite ends; thus, aircraft can be used for air travel but also as targets of terrorism. A state that supports aviation terrorism is responsible for violation of International Aviation Law. Generally speaking, terrorism is a violation of international law. It violates the soverign rights of the states, and the human rights of the individuals. I think that aviation terrorism as becoming an ever more serious issue, has to be solved by internationally agreed and closely co-ordinated measures. We have to contribute more to the creation of a general consensus amongst all states about the need to combat the threat of aviation terrorism.

• The Journal of Korean Society for School & Community Health Education
• /
• v.2 no.1
• /
• pp.67-84
• /
• 2001

This study was conducted to examine beauty shop workers' views of job. Data were collected from the workers in Seoul, Daegu, Pohang, Junjoo, and Kimhae from June 1, 2000 to August 31, 2000. The results of this study are summarized as follows. 1. According to general characteristics of the subjects, 28,7% of them was female; 94.2% 'specialized in hair'; 46.4% 'below twenty nine years old'; 47.1% 'married'; 59.7% 'highschool graduate'; 33.9% 'worked for below three years'; 28.5% 'monthly income of five hundred thousand to nine hundred ninety thousand won'; 62.3% 'working for above twelve hours a day' ; 41.0% 'above five workers' ; 40.6% 'working in city'. 2. 54.8% of the respondents thought that they were in good health. 76.3% of them smoked and 54.8% drank. 62.8% of them did not exercise and 78.7% was under stress. 61.5% responded that they chose the job because of its possibility of professional vocation. 91.0% of them obtained the beauty skill from beauty schools. 3. Among the factors which influenced job satisfaction, 'stable job and life security' was highest(43.9%), while 'interest in the job and amount of pay' was lowest(3.2%). 'Personal ability and use of originality' was 19.4% and 'harmonious relationship with fellow workers' was 18.1%. 'Job environment' was 7.1% and 'harmonious relationship with higher workers' was 4.5%. 4. The level workers' view of job was $113.8{\pm}17.3$ points on the basis of 150 points. On the basis of 75 points, each item showed it points in order of self-development($22.3{\pm}3.8$), service for customers($20.1{\pm}3.1$), vocational mission($15.6{\pm}3.1$), harmony with the others($18.9{\pm}3.5$), working environment($18.6{\pm}3.6$), and working condition($14.3{\pm}5.1$). 5. Among the reasons why they considered leaving the job, 24.0% of them considered it because they could not free time, while 15.4% considered it because undesirable living environment or long distance from home. 15.0% thought it because they could not receive proper treatment as much as they worked and 12.8% thought they overworked. 6. When they move into new working places, they consider such factors as good working environment(24.1%), good place to open their own beauty shops(16.7%), good beauty shop to learn beauty skill(15.6%), chance to have job training(9.5%), and close place from home(9.0%). 7. 40.6% of the respondents wanted to leave the job, while 32.3% of them did not want to leave the job. The intention of leaving the displayed significant difference in the variables of age, working period, monthly income, marital status, the number of workers, location of the shop, rank, and reason of selecting the job. 8. According to the results of a regression analysis of factors which influenced job satisfaction, it was affected significantly by intention of leaving job, the number of workers, health condition, level of stress, and monthly income. The beauty shop workers showed low satisfaction level with working environment, working condition, and working mission, They considered leaving the job because of lack of free time, overwork, poor working environment, improper treatment, etc. Therefore, related professionals and organizations must device adequate measures in order to make them work with pride as creators of beauty.

• Journal of Internet Computing and Services
• /
• v.25 no.1
• /
• pp.99-107
• /
• 2024

Along with economic growth and industrial development, there is an increasing demand for various electronic components and device production of semiconductor, SMT component, and electrical battery products. However, these products may contain foreign substances coming from manufacturing process such as iron, aluminum, plastic and so on, which could lead to serious problems or malfunctioning of the product, and fire on the electric vehicle. To solve these problems, it is necessary to determine whether there are foreign materials inside the product, and may tests have been done by means of non-destructive testing methodology such as ultrasound ot X-ray. Nevertheless, there are technical challenges and limitation in acquiring X-ray images and determining the presence of foreign materials. In particular Small-sized or low-density foreign materials may not be visible even when X-ray equipment is used, and noise can also make it difficult to detect foreign objects. Moreover, in order to meet the manufacturing speed requirement, the x-ray acquisition time should be reduced, which can result in the very low signal- to-noise ratio(SNR) lowering the foreign material detection accuracy. Therefore, in this paper, we propose a five-step approach to overcome the limitations of low resolution, which make it challenging to detect foreign substances. Firstly, global contrast of X-ray images are increased through histogram stretching methodology. Second, to strengthen the high frequency signal and local contrast, we applied local contrast enhancement technique. Third, to improve the edge clearness, Unsharp masking is applied to enhance edges, making objects more visible. Forth, the super-resolution method of the Residual Dense Block (RDB) is used for noise reduction and image enhancement. Last, the Yolov5 algorithm is employed to train and detect foreign objects after learning. Using the proposed method in this study, experimental results show an improvement of more than 10% in performance metrics such as precision compared to low-density images.