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A Fault Tolerant Control Technique for Hybrid Modular Multi-Level Converters with Fault Detection Capability

  • Abdelsalam, Mahmoud;Marei, Mostafa Ibrahim;Diab, Hatem Yassin;Tennakoon, Sarath B.
    • Journal of Power Electronics
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    • v.18 no.2
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    • pp.558-572
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    • 2018
  • In addition to its modular nature, a Hybrid Modular Multilevel Converter (HMMC) assembled from half-bridge and full-bridge sub-modules, is able to block DC faults with a minimum number of switching devices, which makes it attractive for high power applications. This paper introduces a control strategy based on the Root-Least Square (RLS) algorithm to estimate the capacitor voltages instead of using direct measurements. This action eliminates the need for voltage transducers in the HMMC sub-modules and the associated communication link with the central controller. In addition to capacitor voltage balancing and suppression of circulating currents, a fault tolerant control unit (FTCU) is integrated into the proposed strategy to modify the parameters of the HMMC controller. On advantage of the proposed FTCU is that it does not need extra components. Furthermore, a fault detection unit is adapted by utilizing a hybrid estimation scheme to detect sub-module faults. The behavior of the suggested technique is assessed using PSCAD offline simulations. In addition, it is validated using a real-time digital simulator connected to a real time controller under various normal and fault conditions. The proposed strategy shows robust performance in terms of accuracy and time response since it succeeds in stabilizing the HMMC under faults.

Association between Shammah Use and Oral Leukoplakia-like Lesions among Adult Males in Dawan Valley, Yemen

  • Al-Tayar, Badr Abdullah;Tin-Oo, Mon Mon;Sinor, Modh Zulkarnian;Alakhali, Mohammed Sultan
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8365-8370
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    • 2016
  • Background: Shammah is a traditional form of snuff dipping tobacco (a smokeless tobacco form) that is commonly used in Yemen. Oral mucosal changes due to the use of shammah can usually be observed in the mucosal surfaces that the product touches. The aim of this study was to determine the association between shammah use and oral leukoplakia-like lesions. Other associated factors were also determined. Materials and Methods: A cross sectional study was conducted on 346 randomly selected adult males. Multi-stage random sampling was used to select the study location. After completing the structured questionnaire interviews, all the participants underwent clinical exanimation for screening of oral leukoplakia-like lesions Clinical features of oral leukoplakia-like lesion were characterized based on the grades of $Ax{\acute{e}}ll$ et al (1976). Univariable logistic regression and multivariable logistic regression were used to assess the potential associated factors. Results: Out of 346 male participants aged 18 years and older, 68 (19.7%) reported being current shammah users. The multivariable analysis revealed that age, non-formal or primary level of education, former shammah user, current shammah user, and frequency of shammah use per day were statistically associated with the presence of oral leukoplakia-like lesions [Adjusted odds ratio (AOR) = 1.03; 95% confidence interval (CI) : 1.01, 1.06; P=0.006], (AOR=8.65; 95% CI: 2.81, 26.57; P=0.001), (AOR=3.65; 95% CI: 1.40, 9.50; P=0.008), (AOR=12.99; 95% CI: 6.34, 26.59; P=0.001), and (AOR=1.17; 95% CI: 1.02, 1.36; P=0.026), respectively. Conclusions: The results revealed oral leukoplakia-like lesions to be significantly associated with shammah use. Therefore, it is important to develop comprehensive shammah prevention programs in Yemen.

Inquiry about 'The Theory of Brick-Copy' of the Stone Pagoda at Bunhuangsa Temple (신라 분황사탑의 '모전석탑(模塼石塔) 설(說)' 대한 문제 제기와 고찰)

  • Lee, Hee-Bong
    • Journal of architectural history
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    • v.20 no.2
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    • pp.39-54
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    • 2011
  • The Bunhuangsa stone pagoda, constructed in AD. 634, National Treasure no. 30, has been named as 'brick-copied pagoda' since the Japanese-ruling period by scholars. It is said that the Chinese brick pagoda was its precedent model, however the Bunhuangsa Pagoda is the oldest of all the Chinese-style brick pagodas except one, the Sungaksa Pagoda. The Chinese pagoda cannot have been a precedent model to copy due to its complex detail of wood vestige, as the Bunhuangsa pagoda is simple form without ornament. Domestic brick pagodas cannot have been a precedent model to copy as well, because all the domestic brick pagodas are younger than the Bunhuangsa Pagoda. Therefore, the terminology 'brick-copied pagoda' is a fallacy; it is rather that later brick pagoda copied the precedent the Bunhuangsa stone pagoda. The Bunhuangsa Pagoda is simply a piled-up pagoda of thick or thin, big or small slates of stone, facing only one smooth side and therefore needing nothing to relate to brick. The originality of the pagoda is more related to simple piled-up Indian stone stupa rather than Chinese brick pagoda. The roof form of its gradually stepped projection comes from the harmika of the summit of Indian stupa. Contrary to general history, old Silla Dynasty imported Buddhism directly from India by sea. From written national history and by temple foundation history, the Indian Buddhism evangelist possibly made influence to the erecting of temple and pagoda. The original wrong terminology has made a harmful effect gradually to the naming of mass-styled stone pagoda of only carved stepped-roof form after brick-copied pagoda. The false term 'brick-copied pagoda' should be discarded, which comes with superficial observation based on toadyism to China and colonialism to Japan. Instead of the fallacious term, this paper suggests multi-storied 'piled-up pagoda with slate stone.'

Prostate Cancer Incidence in Turkey: An Epidemiological Study

  • Zorlu, Ferruh;Divrik, Rauf Taner;Eser, Sultan;Yorukoglu, Kutsal
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9125-9130
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    • 2014
  • Background: This study aimed to determine the incidence of prostate cancer in Turkey in a population-based sample, and to determine clinical and pathological characteristics of the cases. Materials and Methods: All newly diagnosed prostate cancer patients were included in this national, multi-centered, prospective and non-interventional epidemiological registry study conducted in 12 cities representing the 12 regions of Turkey from July 2008 to June 2009. The population-based sample comprised 4,150 patients with a recent prostate cancer diagnosis. Results: Age-adjusted prostate cancer incidence rate was 35 cases per 100,000 in Turkey. At the time of diagnosis, median age was 68, median PSA level was 10.0 ng/mL. Digital rectal examination was abnormal in 36.2% of 3,218 tested cases. Most patients had urologic complaints. The main diagnostic method was transrectal ultrasound guided biopsy (87.8%). Gleason score was ${\leq}6$ in 49.1%, 7 in 27.8% and >7 in 20.6% of the cases. There was a statistically significant positive correlation between serum PSA level and Gleason score (p=0.000). The majority of patients (54.4%) had clinical stage T1c. Conclusions: This is the first population-based national data of incidence with the histopathological characteristics of prostate cancer in Turkey. Prostate cancer remains an important public health concern in Turkey with continual increase in the incidence and significant burden on healthcare resources.

A Study on the Formation of Working-Class Residential Areas md the Transformation of Housing Types of Firenze, Italy (이탈리아 피렌체의 서민주거지역의 형성과 주거형식의 변화에 관한 연구)

  • Sohn, Sei-Kwan
    • Journal of architectural history
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    • v.13 no.2 s.38
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    • pp.21-38
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    • 2004
  • This study provides a descriptive and analytical account of major aspects of urban development and transformation of housing types of Italian Firenze from the 13th century to the 19th century. It is a typo-morphological depiction of urban spatial structure of the extraordinary city, Firenze, the center of Italian Renaissance. And this study has proceeded on the assumption that the evolving form of the urban structure and housing types cannot be understood without reference to the larger context of political, economic, and social life. Based on these backgrounds, the purpose of this study is threefold: to provide a comprehensive discussion of general characteristics of urban spatial structure of Firenze, and to explain the process of formation of working-class neighborhoods by constructing new city wall in later 13th century, and to discuss transformation of housing types of the working-class neighborhood with understanding the mechanism of existence of housing in the newly formed residential neighborhoods. The development of residential neighborhoods was pursued by 'planned' manner through forming square-shaped blocks, and characterized by the subdivision of larger properties into standardized building lots for the construction of houses. On the bases of documentary evidences, several ecclesiastical institutions are identified as the agents of a distinctive type of development. While the institutions did the major role for developing lands, the construction of houses was done by small scale construction agents with moderate amount of properties. The major housing type of working-class neighborhoods of Firenze has been the 'casa a schiera' characterized by the form of narrow front and long depth. The type was generalized by the newly formed middle and working-class of Firenze which grew their body very rapidly, Even though the type assumed very uniform in its fen there were many variations. And through passing time, the casa a schiera developed to be multi-family housing, and the level of variation became deepen. Eventually, transformation of housing type of Firenze was ended by appearance of the 'casa in linea', which was very similar to modern apartment in its spatial organization.

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Surface deterioration of monolithic CAD/CAM restorative materials after artificial abrasive toothbrushing

  • Sen, Nazmiye;Tuncelli, Betul;Guller, Gultekin
    • The Journal of Advanced Prosthodontics
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    • v.10 no.4
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    • pp.271-278
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    • 2018
  • PURPOSE. The purpose of this in vitro study was to evaluate the effect of abrasive toothbrushing on the surface properties of monolithic computer-assisted design and computer-assisted manufacturing (CAD/CAM) materials stored in food-simulating liquids (FSLs). MATERIALS AND METHODS. Fourty-eight disk-shaped test specimens of each material (Paradigm MZ100/PMZ, Lava Ultimate/LU, Vita Enamic/VE, and Vita Mark II/VMII) with a diameter of 10.0 mm and a thickness of $3.0{\pm}0.05mm$ were prepared. Specimens were divided into 4 subgroups (n=12) and stored in air, distilled water, 0.02 M citric acid, or 75% ethanol/water solution for 7 days at $36.5^{\circ}C$. Then, the specimens were brushed in a multi-station brushing machine under a vertical load of 2.0 N for 3 hours. Surface gloss (GU), roughness (Ra), and hardness (Vickers [VHN]) were measured after storage and brushing simulation. The data sets were statistically analyzed with 2 and 3-way ANOVAs followed by the Tukey's post-hoc comparisons (${\alpha}=.05$). RESULTS. Statistically significant difference was found among the materials concerning the results of surface properties. VMII showed the highest VHN, while PMZ produced the lowest. Storage in FSLs significantly affected the VHN of PMZ and LU. VMII showed the lowest Ra and highest GU irrespective of FSLs and of abrasive toothbrushing. VE, LU, and PMZ produced significant decrease in GU and increase in Ra after toothbrushing. CONCLUSION. Surface properties of monolithic CAD/CAM restorative materials were differently affected by the storage media and abrasive toothbrushing.

Shear strength estimation of RC deep beams using the ANN and strut-and-tie approaches

  • Yavuz, Gunnur
    • Structural Engineering and Mechanics
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    • v.57 no.4
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    • pp.657-680
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    • 2016
  • Reinforced concrete (RC) deep beams are structural members that predominantly fail in shear. Therefore, determining the shear strength of these types of beams is very important. The strut-and-tie method is commonly used to design deep beams, and this method has been adopted in many building codes (ACI318-14, Eurocode 2-2004, CSA A23.3-2004). In this study, the efficiency of artificial neural networks (ANNs) in predicting the shear strength of RC deep beams is investigated as a different approach to the strut-and-tie method. An ANN model was developed using experimental data for 214 normal and high-strength concrete deep beams from an existing literature database. Seven different input parameters affecting the shear strength of the RC deep beams were selected to create the ANN structure. Each parameter was arranged as an input vector and a corresponding output vector that includes the shear strength of the RC deep beam. The ANN model was trained and tested using a multi-layered back-propagation method. The most convenient ANN algorithm was determined as trainGDX. Additionally, the results in the existing literature and the accuracy of the strut-and-tie model in ACI318-14 in predicting the shear strength of the RC deep beams were investigated using the same test data. The study shows that the ANN model provides acceptable predictions of the ultimate shear strength of RC deep beams (maximum $R^2{\approx}0.97$). Additionally, the ANN model is shown to provide more accurate predictions of the shear capacity than all the other computed methods in this study. The ACI318-14-STM method was very conservative, as expected. Moreover, the study shows that the proposed ANN model predicts the shear strengths of RC deep beams better than does the strut-and-tie model approaches.

Fluorescence-in-situ-hybridization in the Surveillance of Urothelial Cancers: Can Use of Cystoscopy or Ureteroscopy be Deferred?

  • Ho, Christopher Chee Kong;Tan, Wei Phin;Pathmanathan, Rajadurai;Tan, Wei Keith;Tan, Hui Meng
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.7
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    • pp.4057-4059
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    • 2013
  • Background: Fluorescence in situ hybridization (FISH) testing may be useful to screen for bladder carcinoma or dysplasia by detecting aneuploidy chromosomes 3, 7, 17 and deletion of the chromosome 9p21 locus in urine specimens. This study aimed to assess the sensitivity, specificity, positive and negative predictive value of FISH in a multi-ethnic population in Asia. Materials and Methods: Patients with haematuria and/or past history of urothelial cancer on follow-up had their voided urine tested with FISH. Patients then underwent cystoscopy/ureteroscopy and any lesions seen were biopsied. The histopathological reports of the bladder or ureteroscopic mucosal biopsies were then compared with the FISH test results. Results: Two hundred sixty patients were recruited. The sensitivity and specificity of the FISH test was 89.2% and 83.4% respectively. The positive (PPV) and negative predictive values (NPV) were 47.1% and 97.9%. By excluding patients who had positive deletion of chromosome 9, the overall results of the screening test improved: sensitivity 84.6%; specificity 96.4%; PPV 75.9% and NPV 97.9%. Conclusions: UroVysion FISH has a high specificity of detecting urothelial cancer or dysplasia when deletion of chromosome 9 is excluded. Negative UroVysion FISH-tests may allow us to conserve health resources and minimize trauma by deferring cystoscopic or ureteroscopic examination.

Organization of Crisis Response Teams and Operating Procedures for Crisis Response Activities in the Food Industry (식품산업체의 위기관리 조직 및 위기대응 절차)

  • Kim, Jong-Gyu;Kim, Joong-Soon
    • Journal of Environmental Health Sciences
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    • v.41 no.3
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    • pp.191-202
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    • 2015
  • Objectives: Promotion of food safety/eradicating adulterated food has been listed as one of the four major issues recently identified for action by the Korean government. Due to the related seriousness, the food industry has been encouraged to take steps to restore consumer confidence. In order to set guidelines for the creation of manuals for the response to a food safety crisis by the food industry, this study provided a suggested organization for a crisis response team and operating procedures for crisis response activities. Methods: The prototypes of an organizational structure and a set of standard procedures for a crisis response system were provided. Results: The results of the study suggested that a crisis response team should be comprised of four divisions of responsibility: information analysis, site response, communication and operational support. The organization chart and the role and functions for each division of the crisis response team should be indicated. Response activities will be more effective when the team features multi-disciplined staffing, such as public relations, food safety/technology/quality, sales/marketing, purchasing, production, distribution/logistics, regulatory affairs/legal, and consumer service specialists. This study created a flow chart for the total crisis response system, which included crisis and normal situations. A crisis response team should be continuously operated for both crisis and normal conditions. This study also suggested a scenario to explain the procedures for crisis response activities. Conclusion: In order to cope more effectively with a food safety crisis, the organizational structure and its functions should be defined clearly, and a detailed set of standard procedures for response activities should be offered.

Manipulation of Cassava Cultivation and Utilization to Improve Protein to Energy Biomass for Livestock Feeding in the Tropics

  • Wanapat, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.3
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    • pp.463-472
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    • 2003
  • Cassava (Manihot esculenta, Crantz), an annual tropical tuber crop, was nutritionally evaluated as a foliage for ruminants, especially dairy cattle. Cultivation of cassava biomass to produce hay is based on a first harvest of the foliage at three months after planting, followed every two months thereafter until one year. Inter-cropping of leguminous fodder as food-feed between rows of cassava, such as Leucaena leucocephala or cowpea (Vigna unculata), enriches soil fertility and provides additional fodder. Cassava hay contained 20 to 25% crude protein in the dry matter with good profile of amino acids. Feeding trials with cattle revealed high levels of DM intake (3.2% of BW) and high DM digestibility (71%). The hay contains tannin-protein complexes which could act as rumen by - pass protein for digestion in the small intestine. As cassava hay contains condensed tannins, it could have subsequent impact on changing rumen ecology particularly changing rumen microbes population. Therefore, supplementation with cassava hay at 1-2 kg/hd/d to dairy cattle could markedly reduce concentrate requirements, and increase milk yield and composition. Moreover, cassava hay supplementation in dairy cattle could increase milk thiocyanate which could possibly enhance milk quality and milk storage, especially in small holder-dairy farming. Condensed tannins contained in cassava hay have also been shown to potentially reduce gastrointestinal nematodes in ruminants and therefore could act as an anthelmintic agent. Cassava hay is therefore an excellent multi-nutrient source for animals, especially for dairy cattle during the long dry season, and has the potential to increase the productivity and profitability of sustainable livestock production systems in the tropics.