• Journal of the Korean Geotechnical Society
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• v.23 no.11
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• pp.67-76
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• 2007

The characteristics of rockfall are determined by virtually all factors and conditions e.g. the physical figure of the slope such as inclination, height, roughness, the elemental figure of the slope such as vegetation and material deposited, and the shape and weight of the rockfall itself. Although it is one of the major factors to be considered in rockfall simulation, little attention has been given to the weight of the rockfall. And, since the size of the rockfall is dominated by joint spacing, the distribution of the rockfall block weight can be predicted as a function of the joint spacing. In this study, the weight distribution of rockfall was estimated by using the method of volumetric joint count, $J_{\nu}$, based on joint spacing, and $RQD-J_{\nu}$. The results indicate that the weight distributions were analogous in two methods, and the distribution was to be $75.3{\sim}76.7%$ for 200 kilograms or lesser, $15.0{\sim}16.6%$ for $200{\sim}400$ kilograms, and $6.7{\sim}9.7%$ for 400 kilograms or more, which show good matches with the actual on-site weight distribution. Therefore, the weight distribution of rockfall suggested in this paper is able to be considered as appropriate data for rockfall simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.715-722
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• 2010

This paper describes a hardware design of hash function processor which implements Korean Hash Algorithm Standard HAS-160. The HAS-160 processor compresses a message with arbitrary lengths into a hash code with a fixed length of 160-bit. To achieve high-speed operation with small-area, arithmetic operation for step-operation is implemented by using a hybrid structure of 5:3 and 3:2 carry-save adders and carry-select adder. It computes a 160-bit hash code from a message block of 512 bits in 82 clock cycles, and has 312 Mbps throughput at 50 MHz@3.3-V clock frequency. The designed HAS-160 processor is verified by FPGA implementation, and it has 17,600 gates on a layout area of about $1\;mm^2$ using a 0.35-${\mu}m$ CMOS cell library.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.4
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• pp.443-455
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• 2012

In this research, a woman matched to the average Korean standard size specification of 21-24 years of age was scanned using Cyberware. Rapidform 2004 was used to separate the body zone into fit zone, action zone and design zone, depending on the function of the lower body. Each divided body zone expanded radially using 'offset' by 1.60mm at the cross section of the waist, and 6.36mm at the hip level. Resultant ease values were 1cm and 4cm along the waistline and hipline (respectively), as recommended in previous research. 2C-AN program and Yuka CAD was used to develop a pant pattern from the enlarged 3D body surface blocks. A total of five pants were constructed using conventional fabrics for light weight formal pants. The appearance of the experimental pants were evaluated by five clothing-major evaluators using a questionnaire that consisted of 21 questions. In addition, functional aspects of the experimental pants were also evaluated by wearer while performing five postures for the measurement of ease of movement. It was found that, the method of regional offset and suggested 3D to 2D pattern development generate reasonably good pant patterns. Among the pattern block arrangements, the method B was evaluated as the best way to generate formal pants from the tight-fit pattern, which fit smoothly over the lower body for maintaining ease of movement.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.8
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• pp.7-14
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• 2011

In this paper we studied a conventional system and propose a new decoding scheme for Space-time Frequency Code with Interleaved System. We also addressed the quasi orthogonal function with Jacket matrices in modern 3GPP LTE uplinked advance system. We also introduce the Partial Interference Cancellation (PIC) group decoding which provides a framework to adjust the complexity-performance tradeoff by choosing the sizes of the information symbols groups.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.12
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• pp.1216-1227
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• 2013

GNSS(Global Navigation Satellite System) is now being widely used in both civilian and military applications where accurate positioning and timing information are required and it is considered as a representative convergence technique in IT-Military application techniques. However, GNSS has low sensitivity level of GNSS receivers and is vulnerable to jamming signal, since the signals come from the satellite located at approximately 20,000 Km above the earth. The studies for the anti-jamming techniques in military applications have been passively performed in the domestic, because the information related GNSS are dependent on the countries that have GNSS. In this paper, we show the effect of jammer ERP by analyzing the link budget of GPS J/S power as a function of distance between jammer and receiver. Also, we categorize the anti-jamming techniques based on the functional block diagram of GNSS receiver structure and analyze the recent anti-jamming GNSS products and their technologies developed in domestic and foreign countries.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.3
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• pp.242-246
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• 2006

Objective : This is to report the criteria of success of intraoral distraction osteogenesis for alveolar augmentation in the severely atrophied alveolar defects through clinical result of 2 cases. Subjects and Methods : Anterior segmental osteotomy was performed and alveolar distractors (Martin and Leibinger, Germany) were applied each in 2 patients with severely defected anterior maxillary area. The osteomized alveolar segments were distracted by 1mm a day after latency period. After the consolidation period implants were installed with removal of distractor. The implants were evaluated clinically and radiographically. Results : In Case I, the distracted bone was directed to the palatal side, and another augmentation treatment - block bone graft, guided bone regeneration - was needed. In Case II, the successful alveolar bone augmentation was achieved. Dental implant was placed on distracted alveolar bone, and showed good osseointegration and good function without any complication. Conclusion : Distraction osteogenesis can be a good choice for alveolar ridge augmentation of severely atrophied ridges. However, the anterior esthetic prosthetics relies on the control of the vector, the kind of distractor, the healing capacity of patient and the etiology of atrophy. Therefore another study of each category would be needed.

• Journal of Satellite, Information and Communications
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• v.9 no.3
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• pp.109-115
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• 2014

This paper suggest meteorological satellite processing software's structure that reduces time and efforts of modification/upgrade. This structure's key feature is "algorithm component" that works within framework and eventually to a complete Meteorological satellite processing system. Most of existing Meteorological satellite system is designed around specific function and data sets which limits range of modification and upgrade. In addition, re-use of current algorithms become difficult although re-use of similar algorithm is the case in many occasions. This inefficiency can be resolved by designing a new framework as a result of detail analysis of collected requirements. A new framework and system architecture has been designed. In addition, operational flow of Satellite image processing framework has been described.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.694-700
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• 2017

Clostridium difficile, which causes pseudomembranous colitis, releases toxin A and toxin B. These toxins are considered to be the main causative agents for the disease pathogenesis, and their expression is associated with a marked increase of apoptosis in mucosal epithelial cells. Colonic epithelial cells are believed to form a physical barrier between the lumen and the submucosa, and abnormally increased mucosal epithelial cell apoptosis is considered to be an initial step in gut inflammation responses. Therefore, one approach to treating pseudomembranous colitis would be to develop agents that block the mucosal epithelial cell apoptosis caused by toxin A, thus restoring barrier function and curing inflammatory responses in the gut. We recently isolated an antimicrobial peptide, Periplanetasin-2 (Peri-2, YPCKLNLKLGKVPFH) from the American cockroach, whose extracts have shown great potential for clinical use. Here, we assessed whether Peri-2 could inhibit the cell toxicity and inflammation caused by C. difficile toxin A. Indeed, in human colonocyte HT29 cells, Peri-2 inhibited the toxin A-induced decrease in cell proliferation and ameliorated the cell apoptosis induced by this toxin. Moreover, in the toxin A-induced mouse enteritis model, Peri-2 blocked the mucosal disruption and inflammatory response caused by toxin A. These results suggest that the American cockroach peptide Peri-2 could be a possible drug candidate for addressing the pseudomembranous colitis caused by C. difficile toxin A.

• Journal of Dental Rehabilitation and Applied Science
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• v.20 no.1
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• pp.43-50
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• 2004

This study was performed to measure the retentive force of dental impression tray according to retention form. The 9 resin beams($30{\times}60{\times}2.5mm$) were made of visible light-curing tray resin according to the surface texture, the size of hole and the number of rim. The resin block was fabricated in width 50mm, length 30mm, heght 40mm to maintain an even hydrocolloid impression material. The retentive force between the resin beam and hydrocolloid impression material was measured by Universal Testing Machine(Zwick Z020, Zwick Co., Germany). The results obtained in this study were as follows : 1. The retentive force of the resin beam with bilateral 4 rims, 2mm holes(9group) was highest(9.18kg), and the polishing resin beam(2group) was worst(4.85kg). 2. There was no significant difference between the polished the resin beam(2group) and the contrast resin beam(1group). 3. The retentive force of the rimmed resin beam was higher than the perforated resin beam. 4. The retentive force of the 2mm perforated resin beam(4group) was higher than the 3mm perforated resin beam(3group). 5. As increasing the number of rim increased the retentive force.

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.17-26
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• 2014

Background: Despite children's unique characteristics that distinguish them from adults, relatively few attempts have been made to measure exposure factors for characterization of children's exposure to hazardous chemicals in child-specific products (CSP). This study was conducted to establish the child-specific exposure factors for exposure and risk assessment of hazardous substances in CSP. Methods: We investigated the exposure factors (e.g., time use of child-products, time and frequency of object-to-body contact, time and frequency of object-to-mouth contact) influencing children's exposure to CSP (e.g., toys, playmats, oil pastels, etc.) in 650 children through a parent-completed questionnaire using a web-based survey. Participants were recruited in five age groups, <1, 1-2, 2-3, 3-6, and 6-12 years of age. Results: The child-specific exposure factors were presented as the mean, median, $95^{th}$ percentile, minimum, and maximum values. Time activity for play mats was the longest among CSP and infants spent more time on them than did elder age groups (189.3-224.7 min/day for <1-2 years vs. 91.2 min/day for 6-12 years). It is apparent that time and frequency of toy block- and plastic toy-to-mouth contact significantly decreased as a function of age. When the variation of CSP use patterns was compared by gender, the only variable that was statistically different between genders was time activity in child-products exposure space. Conclusion: We believe the five child-specific exposure factors suggested in the present study will be valuable for reducing uncertainty in the estimation of chemical exposure during risk assessment of CSP and furthermore, in the appropriate regulations to protect children's health.