• Nuclear Engineering and Technology
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• v.52 no.2
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• pp.381-396
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• 2020

Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part I, finite element (FE) models establishment and validations for both the aircrafts and NPP buildings are performed. (i) Airbus A320 and A380 aircrafts are selected as the representative medium and large commercial aircrafts, and the corresponding fine FE models including the skin, beam, fuel and etc. are established. By comparing the numerically derived impact force time-histories with the existing published literatures, the rationality of aircrafts models is verified. (ii) Fine FE model of the Chinese Zhejiang Sanao NPP buildings is established, including the detailed structures and reinforcing arrangement of both the containment and auxiliary buildings. (iii) By numerically reproducing the existing 1/7.5 scaled aircraft model impact tests on steel plate reinforced concrete (SC) panels and assessing the impact process and velocity time-history of aircraft model, as well as the damage and the maximum deflection of SC panels, the applicability of the existing three concrete constitutive models (i.e., K&C, Winfrith and CSC) are evaluated and the superiority of Winfrith model for SC panels under deformable missile impact is verified. The present work can provide beneficial reference for the integral aircraft crash analyses and structural damage assessment in the following two parts of this paper.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.7
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• pp.1060-1068
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• 2009

The buffalo (Bubalus bubalis) is an important contributor to milk, meat, power, fuel and leather production in many developing countries. Buffaloes can be categorized into Asian and Mediterranean buffaloes. Asian buffalo includes two subspecies known as Riverine and Swamp types. Riverine (water buffalo) and Swamp buffaloes possess different genetics (50 vs. 48 chromosomes, respectively), morphology (body frame, body weight, horn shape and skin color) and behavior (wallowing in mud or water) and thus, are reared and used for different purposes. Low per head milk yield, poor reproductive performance (seasonal breeding behavior, anestrous, and longer calving interval) and low growth rate in buffaloes have been attributed to insufficient supply of nutrients. In many parts of Asia, where the buffalo is an integral part of the food chain and rural economy, irregular and inadequate availability of quality feedstuffs and their utilization are hampering the performance of this unique animal. Balanced nutrition and better management can enhance buffalo productivity. Many efforts have been made in the last few decades to improve nutrient supply and utilization in buffaloes. Recent research on locally available feed resources such as crop residues, and industrial by-products, dietary addition of micronutrients, use of performance modifiers and use of ruminally protected fat and protein sources have shown significant potential to improve growth, milk yield and reproductive performance of buffaloes. However, a number of issues, including establishment of nutrient requirements for dairy and beef, development of buffalo calf feeding systems, nutritional management of metabolic and reproductive anomalies, and understanding and exploitation of the buffalo gut ecosystem, need to be addressed. Extensive coordinated research and extension efforts are required for improved buffalo nutrition in developing countries.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.3
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• pp.305-314
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• 2001

A modified model is proposed for calculation of transitional boundary layer flows. In order to develop the eddy viscosity model for the problem, the flow is divided into three regions; namely, pre-transition region, transition region and fully turbulent region. The pre-transition eddy-viscosity is formulated by extending the mixing length concept. In the transition region, the eddy-viscosity model employs two length scales, i.e., pre-transition length scale and turbulent length scale pertaining to the regions upstream and the downstream, respectively, and a universal model of stream-wise intermittency variation is used as a function bridging the pre-transition region and the fully turbulent region. The proposed model is applied to calculate three benchmark cases of the transitional boundary layer flows with different free-stream turbulent intensity (1%∼6%) under zero-pressure gradient. It was found that the profiles of mean velocity and turbulent intensity, local maximum of velocity fluctuations, their locations as well as the stream-wise variation of integral properties such as skin friction, shape factor and maximum velocity fluctuations are very satisfactorily predicted throughout the flow regions.

• Journal of Digital Convergence
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• v.11 no.9
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• pp.311-318
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• 2013

For face detection techniques, the correctness of detection decreases with different lightings and backgrounds so such requires new methods and techniques. This study has aimed to obtain data for reasoning human emotional information by analyzing the components of the eyes and mouth that are critical in expressing emotions. To do this, existing problems in detecting face are addressed and a detection method that has a high detection rate and fast processing speed good at detecting environmental elements is proposed. This method must detect a specific part (eyes and a mouth) by using Haar-like Feature technique with the application of an integral image. After which, binaries detect elements based on color information, dividing the face zone and skin zone. To generate correct shape, the shape of detected elements is generated by using a bezier curve-a curve generation algorithm. To evaluate the performance of the proposed method, an experiment was conducted by using data in the Face Recognition Homepage. The result showed that Haar-like technique and bezier curve method were able to detect face elements more elaborately.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.2
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• pp.251-257
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• 2012

Human body communication means transmitting and receiving data through human body medium or through free space along with the human body skin. Electric field distribution around the human body between the transmitter and the receiver were calculated at five different frequencies with 5 MHz interval between 10 MHz and 30 MHz. Commercial electromagnetic simulation tool was used for the calculation of E-field distributions applying the Korean standard male model including 29 different kinds of human tissues. After calculating specific absorption rate(SAR) values on back of the hand, it was compared with International Commission on Non-Ionizing Radiation Protection(ICNIRP) human protection guideline. While conductivities(${\sigma}$) and relative permittivities(${\varepsilon}_r$) of the human tissues for each frequency were input as the analyzing parameters, electric field intensities near both hands were integrated along the integral line between the nearby electrodes for the calculation of the transmitting and receiving voltages whose ratio was defined as channel loss. The calculated channel losses were about ($75{\pm}1$) dB and showed nearly flat response all through the evaluated frequencies.

• Journal of Korean society of Dental Hygiene
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• v.11 no.4
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• pp.581-593
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• 2011

Objectives : The purpose of this study was to examine the relationship of the work environments of dental hygienists to their occupational diseases in a bid to provide some information on their health care, health promotion and the prevention of occupational diseases. Methods : The subjects in this study were 300 dental hygienists who worked in Seoul, urban communities involving large cities and rural areas. One-on-one interviews and a self-administered survey were implemented with their consent. Results : The findings of the study were as follows: 1. 60 percent of the dental hygienists investigated replied that they had occupation-related physical symptoms. By the length of service, the dental hygienists who worked for six to 10 years had the most symptoms. 2. Out of the occupation-related symptoms, the most prevalent symptom was a pain in the shoulders and neck(41%), followed by a pain in the lower back, a pain in the legs, a pain in the wrists and skin diseases. The most painful parts of the body were hands and arms. 3. In regard to the relationship between the general characteristics and the intensity of pain, the highest group of the dental hygienists in Seoul replied that they had a severe pain, and the lowest number of those in the large cities gave the same answer. 4. Concerning the cause of occupational diseases, 65.7 percent cited the wrong posture. 5. As to relationship between the general characteristics and regular hospital-visit experiences for the prevention of pain during work hours, many of the dental hygienists who were in their 40s and 50s visited hospitals from time to time, and many of those in their 20s never did that. 6. In regard to links between the general characteristics and an opinion on the necessity of regular education, many of the respondents from Seoul and urban regions involving large cities considered it necessary to receive education on a regular basis. By daily work hours, the highest number of those who worked for eight hours or less considered that necessary, and lots of those who worked for 11 hours didn't consent to that. The gaps between them were statistically significant(p<0.05). Conclusions : Given the findings of the study, daily work hours and length of service were two integral factors to affect the regular hospital-visit experiences and pain, and the wrong posture was identified as the most common cause of occupational diseases. To ensure the successful prevention of occupational diseases, dental hygiene students should be taught the importance of occupational disease before they start to work, and supplementary education should be provided for dental hygienists to work in the right posture.

• Korean Journal of Bronchoesophagology
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• v.3 no.1
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• pp.70-78
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• 1997

The development of preneoplastic and neoplastic squamous cell proliferations of body sites such as the skin, female lower genital tract, and larynx is strongly associated with specific types of human papillomaviruses (HPV). Antitumor $CD^{8+}$ cells recognize peptide antigens presented on the surface of tumor cells by major histocompatibility complex (MHC) class I molecules. The MHC class I molecule is a heterodimer composed of an integral membrane glycoprotein designated the alpha chain and a noncovalently associated, soluble protein called beta-2-microglobulin( $\beta$ -2-m). Loss of $\beta$-2-m generally eliminates antigen recognition by antitumor $CD^{8+}$ T cells. We evaluated the expression of $\beta$-2-m as a potential means of tumor escape from immune recognition and the presence of HPV DNA as a cause of laryngeal squamous cell carcinomas (SCCs). Laryngeal SCCs (n=39) were analyzed for MHC class I expression by immunohistochemistry and for presence of HPV by in situ hybridization technique. The results were as follows : 1) HPV DNA was detected in 10 (25.64%) out of 39 cases in laryngeal squamous cell carcinomas. 2) MHC class I down-regulation (heterogenous and negative expression) in HPV positive lesions was higher than HPV negative lesions. 3) The expression of MHC class I was related to cellular differentiation regardless of T-stage and nodal involvement. In conclusion, HPV was thought to be the etiological factor of SCC of larynx, and we found that the down-regulation of MHC class I was a common phenomenon In laryngeal SCC and may provide a way for tumor cells to escape from immune surveillance.