• Structural Engineering and Mechanics
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• v.59 no.6
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• pp.1095-1120
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• 2016

This paper investigates the change of structural characteristics of steel cable-stayed bridges after cable failure. Cables, considered as the intermediate supports of cable-stayed bridges, can break or fail for several reasons, such as fire, direct vehicle clash accident, extreme weather conditions, and fatigue of cable or anchorage. Also, the replacement of cables can cause temporary disconnection. Because of the structural characteristics with various geometric nonlinearities of cable-stayed bridges, cable failure may cause significant change to the structural state and ultimate behavior. Until now, the characteristics of structural behavior after cable failure have rarely been studied. In this study, rational cable failure analysis is suggested to trace the new equilibrium with structural configuration after the cable failure. Also, the sequence of ultimate analysis for the structure that suffers cable failure is suggested, to study the change of ultimate behavior and load carrying capacity under specific live load conditions. Using these analysis methods, the statical behavior after individual cable failure is studied based on the change of structural configuration, and distribution of internal forces. Also, the change of the ultimate behavior and load carrying capacity under specific live load conditions is investigated, using the proposed analysis method. According to the study, significant change of the statical behavior and ultimate capacity occurs although just one cable fails.

• Journal of Biomedical Engineering Research
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• v.30 no.6
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• pp.529-534
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• 2009

One of the characteristics of the hearing impaired is that their frequency selectivity is poorer than that of the normal hearing. To compensate this, formant enhancement algorithms and spectral contrast enhancement algorithms have been developed. However in some cases, these algorithms fail to improve the frequency selectivity of the hearing impaired. One of the reasons is the acoustic masking among enhanced formants. In this study, we tried to enhance the formants based on the individual masking characteristic of each subject. The masking characteristic used in this study was minimum level difference (MLD) between the first formant to the second formant while acoustic masking was occurred. If the level difference between the two formants in each frame is larger than the MLD, the gain of the first formant was decreased to reduce the acoustic masking that occurred among formants. As a result of the speech discrimination test, using formant enhanced speeches, speech discrimination score (SDS) of the speeches having differently enhanced formants was significantly superior to SDS of the speeches having equally enhanced formants. It means that suppression of the acoustic masking among formants improve frequency selectivity of the hearing impaired.

• Journal of Korean Society for Quality Management
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• v.47 no.1
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• pp.75-86
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• 2019

Purpose: It is essential for the steel industry to produce steel products without unexpected downtime to reduce costs and produce high quality products. A hot strip rolling mill consists of many mechanical and electrical units. In condition monitoring and diagnosis, various units could fail for unknown reasons. Methods: In this study, we propose an effective method to detect units with abnormal status early to minimize system downtime. The early warning problem with various units was first defined. An autoencoder was modeled to detect abnormal states. An application of the proposed method was also implemented in a simulated field-data analysis. Results: We can compare images of original data and reconstructed images, as well as visually identify differences between original and reconstruction images. We confirmed that normal and abnormal states can be distinguished by reconstruction error of autoencoder. Experimental results show the possibility of prediction due to the increase of reconstruction error from just before equipment failure. Conclusion: In this paper, hot strip roughing mill monitoring method using autoencoder is proposed and experiments are performed to study the benefit of the autoencoder.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.285-291
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• 2022

The number of people enrolling in universities is rising due to the simplicity of applying and the benefit of earning a bachelor's degree. However, the on-time graduation rate has declined since plenty of students fail to complete their courses and take longer to get their diplomas. Even though there are various reasons leading to the aforementioned problem, it is crucial to emphasize the cause originating from the management and care of learners. In fact, understanding students' difficult situations and offering timely Number of Test data and advice would help prevent college dropouts or graduate delays. In this study, we present a machine learning-based method for early detection at-risk students, using data obtained from graduates of the Faculty of Information Technology, Dainam University, Vietnam. We experiment with several fundamental machine learning methods before implementing the parameter optimization techniques. In comparison to the other strategies, Random Forest and Grid Search (RF&GS) and Random Forest and Random Search (RF&RS) provided more accurate predictions for identifying at-risk students.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.27.1-27.9
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• 2019

Background: Implants are becoming the first choice of rehabilitation for tooth loss. Even though they have a high success rate, failures still occur for many reasons. The objective of this study is to analyze the reasons for recurring failure at the same site and the results of re-implantation. Methods: Thirteen patients (11 males and 2 females, mean age 60 ± 9.9 years) who experienced implant surgery failure at the same site (same tooth extraction area) two or more times in the Department of Oral and Maxillofacial Surgery, Seoul National University Bundang Hospital, between 2004 and 2017 were selected. The medical records on a type, sites, diameter, and length of implants; time and estimated cause of failure; and radiographs were reviewed. Data were collected and analyzed retrospectively, and the current statuses were evaluated. Results: A total of 14 implants experienced failure in the same site more than two times. Twelve implants were placed in the maxilla, while 2 implants were placed in the mandible. The maxillary molar area was the most common site of failure (57.1%), followed by the mandibular molar, anterior maxilla, and premolar areas (14.3% each). The first failure occurred most commonly after prosthetic treatment (35.7%) with an average period of failure of 3.8 months after loading. Ten cases were treated as immediate re-implantation, while the other 4 were delayed reimplantation after an average of 3.9 months. The second failure occurred most commonly after prosthetic treatment (42.9%), with an average of 31 months after loading; during the healing period (42.9%); and during the ongoing prosthetic period (14.3%). In 3 cases (21.4%), the treatment plan was altered to an implant bridge, while the other 11 cases underwent another implant placement procedure (78.6%). Finally, a total of 9 implants (64.3%) survived, with an average functioning period of 60 months. Conclusions: Implants can fail repeatedly at the same site due to overloading, infection, and other unspecified reasons. The age and sex of the patient and the location of implant placement seem to be associated with recurring failure. Type of implant, bone augmentation, and bone materials used are less relevant.

• Journal of The Korean Association For Science Education
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• v.39 no.6
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• pp.707-715
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• 2019

The self-directed inquiry to improve students' core scientific competency is an important teaching method. Students experience a variety of difficulties in carrying out their inquiry tasks, sometimes fail to produce the desired results, or fail to perform a meaningless inquiry. This study was conducted to identify the causes of difficulties and failures in students' self-directed scientific inquiry. The study involved 16 high school students with experience in science research at science high schools and science-focused high schools. The data collection consisted of in-depth interviews centered on semi-structured open questions. Qualitative data analysis was imputed by finding paragraphs from the interview material that might reveal the difficulties and failures experienced by participants and the reasons for them. The study found that most of the causes of failure were lack of ability, incomplete procedures, and selection of complicated tasks. A variety of cognitive biases, such as overconfidence, planning fallacy, and groupthink, were also analyzed as causes. Based on the results of the study, it is necessary to develop an educational strategy that students can be fully prepared to reduce their trials and errors in a self-directed inquiry maximally.

• Korean Security Journal
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• no.13
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• pp.207-234
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• 2007

This study examines the roles of government and reasons of defeat on 9.11 terror, iraq war between 2001 and 2003. The administration functions critical role of national security. And punctual, accurate information supply capability helps policymaker's decision-making. Hence, information of punctuality and accuracy should be given to policymakers. And without two above written factors, it will result in failing. Information concoction on policymaker's pressure, biased informant, inaccurate information and lack of assembly means under the extensive organization and technologized spying means, Fail to keep information objectivity, leads to information failure. In the context of a series of facts, we shall cover the position of government and reasons of calamities. Two incidents deem as information failure by national security service, but concoction of Iraqi mass destruction weaponry is believed as bush administration's deception on account of political gains. For fully functional government role, governing body should reinforce all aspects of gathering, analyzing, and making use of information more objectively in the first place. In particular, information concoction involving policymakers post massive stumbling block to organized outcome. The thesis presents a prospective view of government position under the U.S. secret agent over 9.11 terror and Iraq war.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7891-7895
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• 2014

Background: Tobacco products continue to be used in large quantities in India despite the mandatory inclusion of pictorial health warnings (PHWs) on all tobacco packaging. The circumstances as to how people could continue the use of tobacco to the point of developing head and neck cancer despite enhanced awareness about the ill effects of tobacco is the main focus of this study. Materials and Methods: This study concerned patients with least 5-years history of tobacco use, having been diagnosed with histopathologically proven malignancies of the hypopharynx, larynx, oropharynx and oral cavity presenting at the Government Medical College-Haldwani, Nainital, India. A total of 183 patients were eligible for inclusion during July 1 2013 - June 30 2014. Of these, 59 patients used smoked tobacco exclusively, 22 patients used smokeless tobacco exclusively, and 102 patients used both forms of tobacco. Among users of smoked forms, 75.2% (n=121) were beedi users, and 24.8% (n=40) were cigarette users. Patients were asked direct questions as to whether they had noticed the presence of PHWs upon tobacco products. The reasons as to why PHWs were not effective in stopping the patients from tobacco use were investigated. Results: Of the 183 patients, 146 reported being aware about the presence of PHWs, and when they were asked reasons as to why they continued tobacco despite being aware of ill-effects, the commonest reason chosen (by 53.4%) was that patients had not regarded themselves as using tobacco heavy enough to cause cancer. Among the 36 patients who reported as being oblivious to the presence of PHWs on tobacco products, 63.9% reported that the products they used never displayed any PHWs, and 36.1% reported never having paid attention to the packaging. The awareness about PHWs was higher among cigarette smokers in comparison to beedi smokers (100% vs 76.1%, p=0.0002). Conclusions: Locally produced and marketed tobacco products such as beedis and oral tobacco often fail to display PHWs. The presence of PHWs without doubt enhances awareness about the carcinogenic risks of tobacco. However, enhanced awareness alone may not be enough, and as elucidated by this study, some persons continue to use tobacco to the point of developing malignancies. The need of the hour is the implementation of legal and economic sanctions discouraging the use of tobacco products.

• Journal of Technology Innovation
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• v.14 no.1
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• pp.147-175
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• 2006

One of the biggest problems of Korean economy is polarization of firms for export and domestic demand and that of conglomerates and SME's achievement. One of the culprits lies weakness of intermediate industry such as machine tool. Since intermediate industry is important path where export performance affects domestic demand and whose actor usually is SMEs with high spill over effect in labor market. Especially, intermediate industry Is vulnerable because of industrial policy biased In backward linkage effect. However if a country fails to develop intermediate industry above some critical point, that country would fall in low-tech equilibrium without growth. In case of benign circle where final goods industry growth leads growth of intermediate industry and again it leads that of final goods industry, it can reach high-tech equilibrium. By contrast, in opposite case where in industrialization latecomer fails to link industries likewise above some critical point that country would fall in low-tech equilibrium without growth. Moreover, for several reasons, machine tool firms of Korea have difficulty in catching up technology above critical point. Firstly. Conglomerate demander neglects their product. Secondly, even after success of development overcoming difficulties they fail to get market share for response of dumping of foreign competitors. And the last one is patent litigation of foreign competitors that incapacitate the technology development. For these, Korean machine tool firms fell in 'middle-income country trap' itself, since they stuck in some extent when they technologically catch up. Consequently, for latecomer country in machine tool industry to leapfrog meaningfully policy support is necessary, Weak intermediate industry does not Induce domestic firms and remained fragile. Therefore, localization, policy should reflect condition of technological catch up more than before, in order to be effective and fruitful. There should be turning point over relationship between conglomerates, major demander of machine tool and SME's, for only with active purchasing of conglomerate Korean machine industry can grow.

• The Journal of Internal Korean Medicine
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• v.23 no.2
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• pp.280-285
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• 2002

Pruritus is [CHECK DEFN] itchy feeling of one's skin. We often face stroke patients who complain about Pruritus. They occasionally fail to fall asleep or have a secondary infection as a result of scratching. For these reasons, severe Pruritus brings down general condition and interferes with recovery. The causes of Pruritus are distributed to from skin diseases and from internal diseases. Especially among the skin diseases, Xerotic Eczema, which is called Senile Eczema causes the dry skin in the elderly, especially lower limb's extensor part. According to the epidemiology, 20% of the old have Xerotic Eczema. In oriental medicine, Pruritus is called Pungsoyang(風瘙痒), Pungyang(風痒), Yangpung(痒風), Sinyang(身痒). The cause of Pruritus is divided into two. One is endogenous factors and the other is exogenous factors. The former are deficiency of blood(血虛), blood fever(血熱), wind-heat due to internal damage(內傷風熱), damp-heat in the liver and gallbladder(肝膽濕熱), endogenous wind stirring in the liver(肝風內動), deticiency syndrome of the spleen(脾虛), deficiency of Yin of the liver and kidneys(肝腎陰虛) and deficiency of the Penetration and Conception Vessels(衝任不足). The latter are wind-cold due to exogenous affection(外感風寒) and wind-heat due to exogenous affection(外感風寒). We report two stroke patients who complained of severe Pruritus They were diagnosed as having Xerotic Eczema by a dermatologist. We regarded their Pruritus as blood fever(血熱) and wind-heat(風熱) and prescribed Sopung-San to these patients. These patients showed significant improvement.