• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.33 no.6
• /
• pp.939-946
• /
• 2023

In the hyper-connected network, which network equipment is diverse and network structure is complex, the attack surface has also increased. In this environment, MTD(Moving Target Defense) technology is being researched as a method to fundamentally defend against cyber attacks by actively changing the attack surface. network-based MTD technologies are being widely studied. However, in order for network address mutation technology to be applied within the existing fixed IP-based system, research is needed to determine what impact it will have. In this paper, we studied the impact of applying network address mutation technology to the existing network protection system. As a result of the study, factors to be considered when firewall, NAC, IPS, and network address mutation technologies are operated together were derived, and elements that must be managed in network address mutation technology for interoperability with the network analysis system were suggested.

• Journal of Soil and Groundwater Environment
• /
• v.6 no.3
• /
• pp.53-59
• /
• 2001

There is a lot of method to manage the insanitary landfill but vertical cutoff walls have been widespreadly used and were installed into the subsurface to act as a barrier to horizontal groundwater flow, The stabilized material such as specialized cement or mixed soil with additives has been generally applied for the materials of the deep soil mixing barrier in korea. The amount of the stabilized material is dependent on the field conditions, because the mixing ratio of the material and the field soil should achieve a requirement in the coefficient of permeability, lower than 1.0$\times$$10^{7}$cm/sec. This study determined the quantity and optimized function ratio of the stabilized material in the formation process of the mixed barrier that was added with stabilized material on the field soil classified into SW-SC under USCS (Unified Soil Classification System). After that the fly ash and lime were selected as an additives an that could improve the function of the stabilized material and then the method to improve the functional progress in the usage of putting into the stabilized material as an appropriate ratio was studied and reviewed. The author used the flexible-wall permeameter for measuring the permeability and unconfined compressive strength tester for compressive strength, and in the view of environmental engineering the absorption test of heavy metals and leaching test regulated by Korean Waste Management Act were performed. As the results, the suitable mixing ratio of the stabilized material in the deep soil mixing barrier was determined as 13 percent. To make workability easy, the ratio of stabilized material and water was proven to be 1 : 1.5. With the results, the range of the portion of the additives(fly ash : lime= 70 : 30) was proven to be 20-40% for improving the function of the stabilized material, lowering of permeability. In heavy metal absorption assessment of the mixing barrier system with the additives, the result of heavy metal absorption was proved to be almost same with the case of the original stabilized material; high removal efficiency of heavy metals. In addition, the leaching concentration of heavy metals from the leaching test for the environmental hazard assessment showed lower than the regulated criteria.

• Journal of Oral Medicine and Pain
• /
• v.31 no.3
• /
• pp.223-229
• /
• 2006

The objectives of this study was to investigate the amount of tooth ablation and the change of intrapulpal temperature by Er:YAG laser as it relates to pulse energy and pulse repetition rate at the identical power and, thereby, to reveal which of the two parameters strongly relates with ablation efficiency and intrapulpal temperature. Extracted healthy human molar teeth were sectioned into two pieces and each specimen was irradiated within the combination of pulse energy and pulse repetition time at the same power of 3W; $300mJy{\times}10Hz$ group, $200mJy{\times}15Hz$ group, and $150mJy{\times}20Hz$ group. Each specimen comprised ten tooth specimens. A laser beam with conjunction of a water flow rate of 1.6 ml/min was applied over enamel surfaces of the specimens during 3 seconds and the ablation amount was determined by difference in weight before and after irradiation. To investigate the temperature change in the pulp according to the above groups, another five extracted healthy human molar teeth were prepared. Each tooth was embedded into resin block and the temperature-measuring probes were kept on the irradiated and the opposite walls in the dental pulp during lasing. When the power was kept constant at 3W, ablation amount increased with pulse energy rather than pulse repetition rate (p=0.000). Although intrapulpal temperature increased with pulse repetition rate, there were no significant differences among the groups and between the irradiated and the opposite pulpal walls, except at a condition of $150y{\times}20Hz$ (p=0.033). Conclusively, it is suggested that ablation efficacy is influenced by pulse energy rather than pulse repetition rate.

• Applied Microscopy
• /
• v.41 no.1
• /
• pp.1-11
• /
• 2011

This experiment was performed to evaluate the morphological responses of the gastric epithelial cells of the mouse, inoculated with Ehrlich carcinoma cells in the inguinal area, following administration of 5-fluorouracil, mitomycin C or Acriflavine-Guanosine compound (AG60). In this study, each mouse was inoculated with $1{\times}10^7$ Ehrlich carcinoma cells subcutaneously in the inguinal area. From next day after inoculations, 0.2 mL of saline, 5-fluorouracil (30 mg/kg), mitomycin C ($400{\mu}g/kg$) or AG60 (30 mg/kg) were injected to the animals every other day, respectively. Each animals were sacrificed after 7th injection and tissue were taken from the gastric mucosa. Thereafter, the ultrathin sections were stained with uranyl acetate and lead citrate. In the 5-fluorouracil-, mitomycin C- or AG60-treated mice, myelin figures and multivesicular bodies within the gastric mucous epithelial cells were observed more frequently than those of the normal control. In the 5-fluorouracil-treated mice, membrane structures containing a few mucous granules in the luminal space were observed. Indeed, bulging cytoplasmic process containing mucous granules protruding into the gastric lumen were observed in the mitomycin Ctreated mice. Therefore, this study suggested that AG60 as compared with 5-fluorourail and mitomycin C may effective medicine without damage to the secretion ability of gastric mucous epithelial cells.

• Korean Journal of Food Science and Technology
• /
• v.21 no.1
• /
• pp.154-163
• /
• 1989

This studies were designed to improve the productivity of L-lysine by protoplast fusion and immobilized system of fusants using strains of Brevibacterium flavum ATCC 21528, Brevibacterium lactofermentum ATCC 21086 and Corynebacterium glutamicum 820. Mutants were isolated with concentration method of $300{\mu}g/ml$ penicillin-G after treatment of $250{\mu}g/ml$ N-methyl-N-nitro-N-nitrosoguanidine. B. flavum $37-2(Hos^-,\;Kan^r,\;AEC^r)$, B. lactofermentum $6-2(Ile^-,\;Val^-,\;Str^r,\;AEC^r)$ and C. glutamicum 57-5$(Met^-,\;Thr^-,\;Rif^r,\;AEC^r)$ were isolated from mutants. Protoplasts were induced by being incubated with $500{\mu}g/ml$ lysozyme of lysis solution for 6 hr and the ratio of protoplast formation and regeneration were ranging from 97-99% and 33-37%, respectively. Fusion frequencies of fusants of BBFL 21, BCFG 37 and BCLG 59 were shown in the range from $1.25{\times}10^{-6}\;to\;5.83{\times}10^{-7}$ under the optimum conditions. The fusant BBFL 21 showed the highest productivity of $411.1\;ng/ml{\cdot}hr$ L-lysine in the lysine productivity broth at $30^{\circ}C$ for 72hr. In the immobilization systems, fusant BBFL 21 was employed in various polymer matrices such as sodium alginate, polyacrylamide, agar and ${\alpha}-carrageena$. The immobilization of sodium alginate showed the highest productivity of $413\;ng/ml{\cdot}hr$ L-lysine in the batch system. Continuous fermentation of immobilization system by using tube fermentor was produced the highest productivity $416.7\;ng/ml{\cdot}hr $ L-lysine under optimum condition.

• Clinical and Experimental Pediatrics
• /
• v.52 no.6
• /
• pp.689-695
• /
• 2009

Purpose : To examine the effect of bosentan, a dual endothelin receptor (ER) antagonist, on the development of monocrotaline (MCT)-induced pulmonary hypertension in rats by especially focusing on the pulmonary vascular morphology changes. Methods : Sprague-Dawley rats were treated as follows: controls received a subcutaneous saline injection, MCT-treated rats received a subcutaneous MCT injection, and bosentan-treated rats received a MCT injection followed by treatment with bosentan (20 mg/kg/day). To assess the effects of ER blockade on the time course, the animals were exsanguinated, and their hearts and lungs were dissected after 7, 14, or 28 days. Results : The mean body weights of the MCT- and bosentan-treated rats were significantly lower than that of the control rats on days 7, 14, and 28. Bosentan administration significantly inhibited the progression of right ventricular hypertrophy on day 28 (right ventricle/[left ventricle＋septum]: $0.71{\pm}0.10$ in MCT-treated rats vs. $0.49{\pm}0.09$ in bosentan-treated rats; P<0.05). Quantitative analysis of peripheral pulmonary arteries revealed that the increase in medial wall thickness after MCT injection was significantly attenuated in the bosentan-treated rats on day 28 ($49.96{\pm}10.06%$ in MCT-treated rats vs. $47.09{\pm}10.48%$ in bosentan-treated rats; P<0.05). In addition, the increase in the number of intra-acinar muscular arteries after MCT injection was reduced by bosentan on days 14 and 28. Conclusion : Bosentan administration in intermediate doses exerts inhibitory effects on lung vascular hypertrophy and right ventricular hypertrophy during the development of MCT-induced pulmonary hypertension in rats.

• Journal of Korean Home Economics Education Association
• /
• v.32 no.2
• /
• pp.159-178
• /
• 2020

This study aimed at exploring male home economics(HE) teachers' identities through narrative inquiry. Considering experiences of HE teachers and diversity in regions, twelve male teachers were chosen, and in-depth interviews were conducted between June 1st and July 31st, 2019. The transcription of the data was transferred to the Hancom Office Hangeul 2010 while the researcher listened to the recordings of the interviews. The total amount of transcription data was 174 pages, and the data were analyzed through open coding, categorization, and category verification. The themes identified as results of this study were as follows: First, 'Coincidence: Breaking the Wall of Prejudice' is related to the experiences that have a great influence on the formation of identity as a male HE teacher: motivation to enter the HE department, educational practice, etc. Through this, the experience of becoming a male HE teacher was recorded. Second, 'Facing: Surviving as a male HE Teacher' captures the current story of male HE teachers and the perspectives of their fellow teachers, family, and friends about male HE teachers. In this section, male HE teachers showed how HE classes and assessments, and their experiences in their lives, influenced their identities. Third, 'Expectations: Growing as a HE teacher' is a story about the future of male HE teachers. The ideal teacher image pursued by male HE teachers was a practical teacher. They hoped that in 10 or 20 years, they would have smooth and professional relationship with students. They advise prospective male HE teachers to become a competent HE teacher regard less of their gender. The significance of this study is that it broke the stereotype of 'HE teachers should be female' and expanded the horizon of HE education by exploring the identities of male HE teachers.

• Restorative Dentistry and Endodontics
• /
• v.32 no.1
• /
• pp.37-46
• /
• 2007

The C-shaped canal system is an anatomical variation mostly seen in mandibular second molars, although it can also occur in maxillary and other mandibular molars. The main anatomical feature of C-shaped canals is the presence of fins or web connecting the individual root canals. The complexity of C-shaped canals prevents these canals from being cleaned, shaped, and obturated effectively during root canal therapy, and sometimes it leads to an iatrogenic perforation from the extravagant preparation. The purpose of this study was to provide further knowledge of the anatomical configuration and the minimal thickness of dentinal wall according to the level of the root. Thirty extracted mandibular second molars with fused roots and longitudinal grooves on lingual or buccal surface of the root were collected from a native Korean population. The photo images and radiographs from buccal, lingual, apical direction were taken. After access cavity was prepared, teeth were placed in 5.25% sodium hypochlorite solution for 2 hours to dissolve the organic tissue of the root surface and from the root canal system. After bench dried and all the teeth were embedded in a self-curing resin. Each block was sectioned using a microtome (Accutom-50, Struers, Denmark) at interval of 1 mm. The sectioned surface photograph was taken using a digital camera (Coolpix 995, Nikon, Japan) connected to the microscope. 197 images were evaluated for canal configurations and the minimal thickness of dentinal wall between canal and external wall using 'Root Thickness Gauge Program' designed with Visual Basic. The results were as follows : 1. At the orifice level of all teeth, the most frequent observed configuration was Melton's Type C I (73%), however the patterns were changed to type C II and C III when the sections were observed at the apical third. On the other hand, the type C III was observed at the orifice level of only 2 teeth but this type could be seen at apical region of the rest of the teeth. 2. The C-shaped canal showed continuous and semi-colon shape at the orifice level, but at the apical portion of the canal there was high possibility of having 2 or 3 canals 3. Lingual wall was thinner than buccal wall at coronal, middle, apical thirds of root but there was no statistical differences.

• Korean Journal of Heritage: History & Science
• /
• v.56 no.1
• /
• pp.182-205
• /
• 2023

The use of royal artificial flowers was finally found through schematics and records in Wonhaeng Eulmyojeongri Uigwe, which organized the procession to Hwaseong in 1795. The results of classifying the uses of artificial flowers in the brthday banquet at Bongsudang Hall in 1795 and considering the shape, user, and usage are as follows. According to literature records, artificial flowers were made with high-quality materials such as gold, silver, and silk thread in the early period, but were mainly made of paper in the later period. Artificial flowers were used for decorating official hats, Bongsudang Hall, and banquet tables. The Sagwonhwa was used for decoration of the official hats of members of the royal family, and the one on the top was called Eosam-Sagwonhwa. At the birthday banquet inBongsudang Hall, King Jeongjo and Hyegyeonggung used the Eosam-Sagwonhwa and put it on the right side of the official hats. Officials put peach blossom with two petals on the left side of the official hats for decoration. The artificial flowers for decoration of the official hats of musicians and dancers were more expensive and flashier than the officials' ones. Depending on the dance, several artificial flowers were inserted into the official hats. When measuring the size of artificial flowers, the scale used was when making a ceremonial article. For artificial flowers for decoration of the banquet hall, red and white peach blossoms were placed in two jars with dragons painted on them and them placed on two red-painted tables, respectively. The table and jar with flowers were tied together with a red cotton string and fixed so as not to fall over. The artificial flowers for decoration of the banquet table of King Jeongjo, Hyegyeonggung, and the king's sisters were a large lotus, medium-sized lotus, peony, rose, and specially made peach flowers. The artificial flowers for decoration of the banquet table of guests and officials were small lotuses and peach blossoms. The artificial flowers used in the birthday banquet at Bongsudang Hall the most were peach blossoms, and peaches had the meaning of longevity and exorcism. It is expected that the above research results will be helpful in understanding the characteristics and usage of artificial flowers in the period of King Jeongjo and use in reproducing royal feasts and producing traditional cultural contents.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.28 no.2
• /
• pp.139-144
• /
• 2015

Recently, to realize sound-absorbing structures, we have to insert sound-absorbing materials into wall. These shapes are taken limitations because sound-absorbing materials should be fixed. Therefore, the sound absorption is changed by environment that used the sound-absorbing materials. On the other hand, we will take same effect without sound-absorbing material, if we change the shape of wall to sound absorbing structure. If we use this sound absorbing structure, we can get benefits by removing limitation of materials. Therefore we suggest perforated plate for effective sound-absorbing structure. We confirmed the function of sound-absorption of this structure using equivalent property. Then, we found the similarity between perforated plate and resonator. Also, we verify these theories through computer simulation by FEM(Finite Element Method). Finally, we validated that perforated plate has function of sound absorption without sound-absorbing material. This perforated plate is used for sound-absorbing material of buildings and transportations such as vehicle, train etc. Also, these results could be further used basic tool for design of sound-absorption structure.