• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.6
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• pp.802-812
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• 1998

Safety related to electric field exposure for the personnel of high voltage power plant and substation is of importance. To analyze the induced current influencing on human body in this paper, we calculate directly capacitance in three dimension which is complex and time consuming, as not to separate the voltage source and the induced object using a effective modeling technique. The proposed algorithm in this paper has been applied to 765 kV high voltage transmission line to evaluate human hazard for the induced current through the case study. As the results, the short circuit current of human body has been identified in the range of 0.3 mA to 6.8 mA. Closing to transmission line, this range of short current can exceed 5 mA that ANSI recommended let-go current. Therefore, it is necessary to countermeasure such as putting on conductive clothing in live-line maintenance of transmission line.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.3
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• pp.113-123
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• 2007

This paper presents a high-performance elliptic curve cryptographic processor over $GF(2^m)$. The proposed design adopts Lopez-Dahab Montgomery algorithm for elliptic curve point multiplication and uses Gaussian normal basis for $GF(2^m)$ field arithmetic operations. We select m=163 which is the smallest value among five recommended $GF(2^m)$ field sizes by NIST and it is Gaussian normal basis of type 4. The proposed elliptic curve cryptographic processor consists of host interface, data memory, instruction memory, and control. We implement the proposed design using Xilinx XCV2000E FPGA device. Based on the FPGA implementation results, we can see that our design is 2.6 times faster and requires significantly less hardware resources compared with the previously proposed best hardware implementation.

• The Journal of the Korea Contents Association
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• v.8 no.5
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• pp.9-18
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• 2008

Web-services have originally been devised to share information as open services. In connection with it, hacking incidents have surged. Currently, Web-log analysis plays a crucial clue role in detecting Web-hacking. A growing number of cases are really related to perceiving and improving the weakness of Web-services based on Web-log analysis. Such as this, Web-log analysis plays a central role in finding out problems that Web has. Hence, Our research thesis suggests Web-DoS-hacking detective technique In the process of detecting such problems through SOM algorithm, the emergence frequency of BMU(Best Matching Unit) was studied, assuming the unit with the highest emergence frequency, as abnormal, and the problem- detection technique was recommended through the comparison of what's called BMU as input data.

• Fire Science and Engineering
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• v.30 no.1
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• pp.49-56
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• 2016

This paper numerically examines, straight and twisted electrical heat trace installations for their anti-freezing effects on water inside a pipe. The unsteady incompressible Navier-Stokes equations coupled with an energy equation were solved to compare the two installation methods. The heat conduction of the pipe with a heat source interacts with the natural convection of the water, and the conjugate heat transfer was considered using a commercial code (ANSYS-FLUENT) based on a SIMPLE-type algorithm. Numerical experiments, were done to investigate the isotherms and the vector fields in the water region to extract the evolutions of the minimum and maximum temperatures of the water inside the pipe. There was no substantial difference in the anti-freezing effects between the straight and twisted. Therefore, the straight installation is recommended after considering the damage and short circuit behavior of the electrical heat trace.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.6
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• pp.107-115
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• 2002

A parametric study has been conducted to evaluate the effects of finite element modeling methods on the internal loads, sizing and the weight of the multi-spar aircraft wing structures. The wing is idealized into total 18finite element models and subjected to 4typical external load conditions. An automatic sizing algorithm based on MSC/NASTRAN and MSC/PATRAN is developed. The results show that the critical part affection the internal loads and weight of the structure is wing skin. Effect of modeling of the spar and rib on the structural behavior is not manifest. On the contrast to the general expectation, the models using the bending-resistant elements show the heavier weight than ones by the elements without bending stiffness. From this results, designers of multi-spar wing are recommended to construct the finite element model considering the bending stiffness, or to check the characteristics of the structure before modeling.

• Journal of Digital Contents Society
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• v.19 no.5
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• pp.845-852
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• 2018

This study has developed a preventive launcher from smartphone addiction for the digital generation and the contents recommendation based on machine learning which used multiple and collective intelligence. This could provide convenient digital nurturing experience for the parents who fear their children's over use of digital devices and also suggest individually adaptive digital learning methods that enhance the learning efficiency and pleasurable and safe learning environment for the children. Suggested application is a kind of gamification launcher that protects children from harmful contents and from smartphone addiction with time limit settings. For parents who find difficulty choosing from various kinds of contents and applications for education, this suggested system could provide a learning analytic report based on big data after collecting and analyzing the data of their children's learning and activities and recommend contents necessary for their kids using recommended algorithm by collective intelligence.

• The KIPS Transactions:PartB
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• v.10B no.5
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• pp.509-514
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• 2003

The virtual bronchoscopy was implemented using chest CT images to visualize inside of tracheo-bronchial wall. The optical endoscopy procedures are invasive, uncomfortable for patients and sedation or anesthesia may be required. Also, they have serious side effects such as perforation, infection and hemorrhage. In order to determine the navigation path, we segmented the tracheo-bronchial wall from the chest CT image. We used the coordinates as a navigation path for virtual camera that were calculated from medial axis transformation. We used the perspective projection and marching cube algorithm to render the surface from volumetric CT image data. The tracheobronchial disease was classified into tracheobronchial stenosis causing from inflammation or lung cancer, bronchiectasis and bronchial cancer. The virtual bronchoscopy is highly recommended as a diagnosis tool with which the specific place of tracheobronchial disease can be identified and the degree of tracheobronchial disease can be measured qualitatively, Also, the virtual bronchoscopy can be used as an education and training tool for endoscopist and radiologist.

• Journal of Radiation Protection and Research
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• v.28 no.1
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• pp.43-50
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• 2003

This study describes a practical method for interpretation of bioassay results of inhaled uranium to assess the committed effective doses both for chronic and acute intake situations. Organs in the body were represented by a series of mathematical compartments for analysis of the behavior of uranium in the body according to the gastrointestinal track model, respiratory track model and biokinetic model recommended by the ICRP. An analytical solutions of the system of balance equations among the compartments were obtained using the Birchall's algorithm, and the urinary excretion function and the lung retention function of uranium were obtained. An initial or total intakes by intake modes were calculated by applying excretion and retention functions to the urinary uranium concentration and the lung burden measured with a lung counter. The dose coefficients given in ICRP 78 are used to estimate the committed effective doses from the calculated intakes.

• Journal of the Korean Institute of Gas
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• v.4 no.3 s.11
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• pp.19-25
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• 2000

In order to prevent secondary disaster such as gas explosion which comes after a devastating magnitude earthquake, the seismic monitoring and transmission system for natural gas governor station was developed. To measure ground motions precisely and operate the seismic monitoring system efficiently, the position and method of accelerometer installation were recommended by the analysis of ground noise patterns of governor station. For making a decision on prompt shut-off of gas supplies in the event of a great earthquake, the real-time calculation algorithm of PGA(Peak Ground Acceleration) and SI(Spectrum Intensity) were developed and it has been implemented in the seismic monitoring and transmission system.

• The Journal of Korean Obstetrics and Gynecology
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• v.21 no.4
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• pp.193-206
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• 2008

Purpose: In spite of many arguments on the result of WHI (Women's Health Initiative) study, no one can deny the necessity for researches on the alternative treatment to HRT (hormone replacement therapy). In this study, the author wanted to investigate the method of precedent acupuncture RCTs (randomized controlled trials) to make out the appropriate acupuncture study design on postmenopausal and perimenopausal hot flashes in Korea. Methods: Precedent studies were investigated using Pubmed search and key-words "acupuncture and hot flash", "acupuncture and menopause", "acupuncture and vasomotor", limited to RCT, from 2000 to 2008 April. Results: As a result. 10 studies were searched. In the hereafter studies, multi-center clinical trials which consist of population group of postmenopausal and perimenopausal women that would be pre-stratified and more than 50 patients per treatment arm seem adequate. Sham control study can make out the proper consequence because many people are get used to acupuncture in Korea. Flexible choice of acupoints addressed an individual's symptoms using standardized algorithm is recommended. Treatment consist of 4 weeks' observation, 11 acupuncture sessions during 7 weeks, follow-up of 3 months or more after treatment and hot flash score as a primary outcome measure seem appropriate. After all, higher level of description according to global standard must be obtained in the study report and publishing. Conclusion: The researchers should develope the methodology of acupuncture clinical trial on the postmenopausal and perimenopausal hot flashes.