• Restorative Dentistry and Endodontics
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• v.35 no.2
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• pp.88-95
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• 2010

The purpose of this study was to compare the root canal shaping ability of 4 rotary NiTi instruments in simulated root canals. For the preparation of thirty two curved root canals, Mtwo instruments using "single length"technique, and Profile, ProTaper Universal, and K3 using crown-down technique (N = 8) were used. All canal samples were prepared by reaching an apical canal size of #30. Pre- and post-instrumentation digital images were recorded and an assessment of canal shape was determined using a computer image analysis program SigmaScan Pro (Systat Software Inc., San Jose, CA, USA). The changes of the dimension of inner walls of canals, (2) the changes of the dimension of outer walls of canals, and (3) the centering ratio were measured at 7 measuring points, and then data were statistically analyzed using one-way ANOVA and Duncan's test. The results were as below; 1. The root canal shaping ability of Profile was significantly faster than that of other rotary NiTi instruments (p < 0.05). 2. The deformation and fracture of all instruments used for this study were not experienced. 3. In the degree of changes of the dimension of inner walls of canals, Profile demonstrated the lowest changes of the dimension of inner walls of canals except at the measuring points of the 1 and 2 mm (p < 0.05). However, the ProTaper Universal showed the highest changes of the dimension of inner walls of canals at all measuring points (p < 0.05). 4. In the degree of changes of the dimension of outer walls of canals, Mtwo demonstrated the lowest changse of the dimension of outer walls of canals except at the measuring point of the 1 mm (p < 0.05). However, Profile exhibited the highest changes of the dimension of outer walls of canals at the measuring points of 3 and 4 mm and ProTaper Universal and K3 showed the largest changes of the dimension of outer walls of canals at the measuring points of 1, 2, 6, and 7 mm (p < 0.05). 5. In degree of centering ratio, Profile demonstrated the least centering ratio comparing with the centering ratio shown by other NiTi instruments at the measuring points of 1, 4, 5, and 6 mm. Results suggest that in the coronal part of canal preparation, active cutting files such as ProTaper Universal may efficiently flare the canal orifice and form a better taper, and in the apical part of the canal, files which have a better centering ability such as Profile may maintain the original canal curvature and reduce the shaping time.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.648-657
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• 2021

This study was conducted to estimate the volume growth by forest type and major species using the national forest resource inventory and to predict the final age of maturity by deriving the mean annual increment (MAI) and the current annual increment (CAI). We estimated the volume growth using the Chapman-Richards model. In the volume estimation equations by forest type, coniferous forests exhibited the highest growth. According to the estimation formula for each major species, Larix kaempferi will grow the highest among coniferous tree species and Quercus mongolica among broad-leaved tree species. And these estimation formulas showed that the fitness index was generally low, such as 0.32 for L. kaempferi and 0.21 for Quercus variabilis. In the analysis of residual amount, which indicates the applicability of the volume estimation formula, the estimates of the estimation formula tended to be underestimated in about 30 years or more, but most of the residuals were evenly distributed around zero. Therefore, these estimation formulas have no difficulty estimating the volume of actual forest species in Korea. The maximum age attained by calculating MAI was 34 years for P. densiflora, 35 years for L. kaempferi, and 31 years for P. rigida among coniferous tree species. In broad-leaved tree species, we discovered that the maximum age was 32 years for Q. variabilis, 30 years for Q. acutissima, and 29 years for Q. mongolica. We calculated MAI and CAI to detect the point at which these two curves intersected. This point was defined by the maximum volume harvesting age. These results revealed no significant difference between the current standard cutting age in public and private forests recommended by the Korea Forest Service, supporting the reliability of forestry policy data.

• Cross-Cultural Studies
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• v.50
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• pp.77-101
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• 2018

Even in our modern era, the projection of monsters in the recent literature contains the critical imagination of human existence for the posthuman age. The meaning of the monster-abject, especially as from the perspective of feministic criticism, contains criticism of the violent and oppressive patriarch as observed in the modern times. This article focuses on the gendered imagination of the discussions of the "abject" discussed by Julia Kristeva, and the "monstrous femine" discussed by Barbara Creed. Kim Eon-Hee's poems and Han Kang's novels, which have been examined extensively for analysis, show that the practical strategy of abject that goes beyond hate and sublime, wonder and joy through the imagination and concepts of monsters. The monster-abject strategy of Kim Eon-Hee's poem can be summarized by the narrative method of mirroring and the imagination of the truncated body. Mirroring falsification, which mimics the male speaker, is a method that some feminists strategically utilize in relation to the problem of female aversion in recent years as noted in the literature. In Kim Eon-Hee's poem, "becoming a man" and "imitating a man," through the method of mirroring appear as an image of cutting to dismantle the body. In that way, the narrative strategy of the abject that draws out abominations and bizarre effects which contains a strong critique of the patriarchal dominant ideology. The monster-abject strategy of Han-Kang's novel is embodied through the being of plants and the process of vegetarian-anorexia process. The world of the adject which was oppressed in the Han-Kang's novel, returns to the senses of the body through the symbol of the body. It is noted that the fictional characters who realize the repressed desire through the pathological symptom expressed by the female, go on to body perform active transformation. The sense of a body in a novel is not only a rejection of the world of animalman-civilization, but also a radically questioning of the noted and recognized boundaries between human beings and non-human being entities. The two writer's works show that the imagination of the monster-adject is not limited to rejecting the existing gender categories, but also goes in the direction of exploring the possibilities of various associated gender actions.

• Korean Journal of Heritage: History & Science
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• v.52 no.3
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• pp.56-73
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• 2019

This paper aims to establish the technical style of roof tiles by analyzing East Asian roof tile making techniques. It will examine the existing main research data, such as excavation results and the subsequent analysis of the roof tiles' production traces, as well as references and transmitted techniques. Regions are grouped according to technical similarity, then grouped again by artistic styles of pattern and shape and by the technical styles of tools, procedures, and manpower plans. Accordingly, intends to find out whether an understanding of technical style can facilitate an understanding of not only cultural aspects, but also the causality of techniques. Korean, Chinese and Japanese tools were examined, and procedures for making roof tiles were classified into 4 groups. In a superficial way, China, Okinawa, Korea, and Honshu share similar technical traits. Research of procedural details and manpower plans revealed characteristics of each region. As a result, comparisons were made between each region's technical characteristics attempting to investigate their causes. The groups were classified according to their possessing techniques, but it was revealed that East Asia's shared production techniques were based on architectural methodss. The skill of "Pyeon Jeol(Clay Cutting)" classified according to its possessing techniques, turned out to be one such technique. Also, the procedure of technical localization based on the skill of "Ta-nal(Tapping)" showed that the condition of this technique was the power to localize in response to a transfer of techniques. Previous comparison parameters of artifacts would have been a similarity of style originated from exchanges between regions and stylistic characteristics of regions decided by the demander's taste of beauty. This methodology enlarges cultural perception and affords a positive basis of historical facts. However, it suggests the possibility of finding cultural aspects' origins by understanding the technical style and seeing same result in view of "technology culture."

• The Journal of the Petrological Society of Korea
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• v.28 no.3
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• pp.157-169
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• 2019

Pseudotachylytes, produced by frictional heating during seismic slip, provide information that is critical to understanding the physics of earthquakes. We report the results of occurrence, structural characteristics, scanning electron microscopic observation and geochemical analysis of pseudotachylytes, which is presumed to have formed after the Late Cretaceous in outcrops of the Paleoproterozoic granitic gneiss on the Bulil waterfall of the Jirisan area, Yeongnam massif, Korea. Fault rocks, which are the products of brittle deformation under the same shear stress regime in the study area, are classified as pseudotachylyte and foliated cataclasite. The occurrences of pseudotachylyte identified on the basis of thickness and morphology are fault vein-type and injection vein-type pseudotachylyte. A number of fault vein-type pseudotachylytes occur as thin (as thick as 2 cm) layers generated on the fault plane, and are cutting general foliation and sheared foliation developed in granitic gneiss. Smaller injection vein-type pseudotachylytes are found along the fault vein-type pseudotachylytes, and appear in a variety of shapes based on field occurrence and vein geometry. At a first glance fault vein-type seudotachylyte looks like a mafic vein, but it has a chemical composition almost identical to the wall rock of granitic gneiss. Also, it has many subrounded clasts which consist predominantly of quartz, feldspar, biotite and secondary minerals including clay minerals, calcite and glassy materials. Embayed clasts, phenocryst with reaction rim, oxide droplets, amygdules, and flow structures are also observed. All of these evidences indicate the pseudotachylyte formed due to frictional melting of the wall rock minerals during fault slip related to strong seismic faulting events in the shallow depth of low temperature-low pressure. Further studies will be conducted to determine the age and mechanical aspect of the pseudotachylyte formation.

• Korean Journal of Plant Resources
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• v.32 no.2
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• pp.116-123
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• 2019

Angelica gigas Nakai (AGN) is a traditional medicinal herb especially in Korea. It contains pyranocoumarins, which are major active components including decursin (D) and decursinol angelate (DA). This study was carried out to determine the change in active component content and antioxidant activity depending on the root diameter of AGN. Several processing steps are involved to use AGN roots as medicine. The dried AGN roots are divided into body (B), thick root (TkR), medium root (MR) and thin root (TnR) according to their diameter before cutting into medicine. The recovery rates of each root parts per 100 kg were measured as $32.3{\pm}2.5$, $9.0{\pm}1.0$, $39.3{\pm}2.1$ and $15.0{\pm}1.0%$, respectively and the mean diameters were measured as $51.95{\pm}4.55$, $7.05{\pm}0.89$, $2.88{\pm}0.49$ and $1.57{\pm}0.32mm$. Two index components, D and DA, were analyzed. The change of both D and DA content showed a similar tendency. Both D and DA content were increased as the root diameter decreased (higher in TnR). In addition, antioxidant activity was higher in B and TnR, and lower in TkR and MR than control. This study showed that the thinner the root diameter, the higher the D and DA content in AGN roots and that TnR has excellent antioxidant activity compared to other root parts, suggesting that the thinner root part of AGN could be used as a potential material.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.1
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• pp.57-68
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• 2021

In order to collect basic data for the improvement of fishing systems in coastal improved stow net fishery, a questionnaire survey and on-site hearing were conducted from May 10 to June 11, 2019 on the basic items of coastal improved stow net fishery and safety accidents that occurred during fishing operation. The questionnaire for the survey on the actual conditions of coastal improved stow net fishery consisted of a survey on basic matters (six questions) and a questionnaire (six questions) on safety accidents occurring during fishing operation. The results of the survey on basic items were analyzed by region (Incheon, Seocheon, Gunsan and Mokpo), by the captain's age (less than 50 years of age, 50 to 60 years and more than 60 years of age), by the captain's career (less than 20 years, 20 to 30 years, 30 to 40 years and more than 40 years) and by the age of fishing vessel (less than 10 years, 10 to 20 years and more than 20 years). According to the survey on basic items of coastal improved stow net fishery such as the captain's age, the captain's career, the age of fishing vessel, the fishing nets in use, the crews on board and the operation days per voyage by region, the average captain's age was 55.7 years, the average captain's career was 20.5 years, the average age of fishing vessels was 9.0 years, the average numbers of nets used by fishing boats was 14.0 sets, the average numbers of crew on board a fishing boat was 4.4 persons and the average numbers of operation days per voyage was 4.9 days (p < 0.05). As a result of the survey on safety factors during fishing operations, such as experience of ship accidents, major causes of ship accidents experienced, causes of ship accidents (first priority), experience of human accidents, major causes of human accidents, and causes of human accidents (first priority), more than 96% of the respondents experienced ship accidents including collisions with other vessels or fishing gear during fishing operations. The most significant cause of the accident was the other's fishing gear installed in the fishing grounds. The first possible causes of ship accidents during fishing operations were found to be other fishing gear installed in fishing grounds, steering or engine failure, and inability to avoid accidents during casting and hauling nets. The survey of the experience of human accidents, such as injuries or sea falls, showed that more than 90% of the respondents experienced human accidents during fishing operations. The most important cause of accidents experienced during fishing operations was stucked in a fishing gear during casting and hauling nets. The first important causes of accidents during fishing operations were movement of the fishing gear during casting and hauling nets, damage of the fishing gear such as rope cutting. The results are expected to be provided as a basic data to prevent safety accidents occurring during fishing operation and improve the fishing system in the coastal improved stow net fishery.

• Conservation Science in Museum
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• v.24
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• pp.1-16
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• 2020

This paper presents the process of re-conservation and the results of research on the production method of the Iron Sword with Ring Pommel with Three-Pointed Leaf Decoration, one of the excavation findings from Tomb No. 55 in the Dalseong Ancient Tomb Complex in Daegu. This iron sword is a double weapon with two large swords housed within a single sheath. Four smaller swords are attached to the surface of the sheath, two on the upper portion and the other two below. It is the only such two-in-one weapon excavated intact thus far from an ancient Korean tomb. The records show that it underwent conservation treatment twice in the past. In this study, it was subjected to conservation treatment again to replace the stiffener in some cracking areas, and its material, composition, and production method were analyzed by CT, XRF analysis, and stereoscopic microscopy. The sword is mainly made of copper, but the golden component contains both gold and mercury, which suggests that the copper was plated in gold using mercury amalgamation. The examination of the production methods indicates that it was intended more to demonstrate the authority of its owner rather than to serve any practical use. The two upper small swords on the sheath were made in the same manner as the main swords, and the two small lower swords were cut from a single metal sheet. The sheath was made by cutting two metal sheets. Supports were used to attach the two small swords to the upper portion of the sheath, while the lower portion of the sheath was slit to allow the other two small swords to be inserted into it. The ring pommels of the main swords have a three-pointed leaf decoration. As for the other designs, the handle of the main sword features a series of semicircles, the decorative bands on the sheath have waves in dots, and the fish tail of the sheath shows diagonal lines of dots.

• Korean Journal of Heritage: History & Science
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• v.55 no.1
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• pp.51-61
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• 2022

Earthenware horn cups with horse head decorations were excavated from Tomb No. 7 of Bokcheon-dong, Dongraegu, Busan Metropolitan City. Made of earth in the shape of a horn, these cups are considered to have been used to drink alcohol or beverage. Large numbers of earthenware horn cups of various shapes were excavated from tombs located in the old territories of Silla and Gaya. A pair of earthenware horn cups were excavated from Tomb No. 7, and the two cups are almost identical in overall shapes and manufacturing techniques despite different sizes. Conservation treatment was carried out for the bigger one of the two horn cups this time. There are two cracks toward the horse head decorations around the mouth with missing parts observed. The chest of the horse touches the ground with one side decorating the horse head and the other side facing the conical mouth of the horn cup. It is in the U shape, striking a balance based on two legs attached behind. The surface of the horn cup was made with a potter's wheel, and the connection to the horse head has traces of cutting and trimming. The horse head is expressed realistically with its features including the ears, eyes, nose, and mouth well apprehended and its color is grey This study intended to investigate manufacturing techniques of the artifact by examining its internal structure through the condition survey in a non-destructive way. CT imaging was used to figure out its manufacturing techniques and to diagnose its condition, and accordingly the scientific conservation treatment was conducted to stabilize the artifact. The precise diagnosis on conservation condition found that there are two chips in the spout with their cracks extended. One of the chips is connected with separation added to the crack. The material which has been used for connection in the past was collected for the infrared spectroscopic analysis, which was identified to be nitrocellulose resin for the connection. Therefore, this conservation treatment focused on removing the old material and preventing the spread of cracks. Before conservation treatment, the condition survey and scientific examination for the artifact were carried out to secure data about the earthenware horn cup with horse head decorations(Treasure). Based on them, effective plans for its conservation treatment was sought for and then existing adhesive was safely removed, and restoration material was selected to take into account its reversibility. In addition, the conservation treatment according to optimal methodologies was conducted through the consultation meeting with experts.

• 한국노년학
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• v.29 no.1
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• pp.149-175
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• 2009

The purpose of this research is to analyze the overall problems at the moment of October 2008, and then to find the improvements of home-help services of the Long-Term Care Insurance(LTCI), which has been revealed many problems since it was released in July 2008. The research uses the literature survey which analyzes 2nd-hand materials studied by other people already, and survey research was executed from active social workers in the area of LTCI. Based on the policy analysis framework of Gilbert and Specht, all the data are analyzed in the scopes of client·benefit(service)·finance·transferring system. This research has found the problems in each scope of home-help services of the LTCI. Firstly, the client system has some problems in mismatching between registered and service clients, estimating client number, and judging service levels. Secondly, the service system reveals deficiency in professionality of social workers, service quality lowering by loose qualification criteria on workers, non-reasonable limitation of service time available, and the same fare system applied to visiting-help service in spite of different levels. Thirdly, in financing system, clients need to pay additional money to get extra services such as meal, hair cutting, bathing etc., due to government financial support stopped, some organizations have to reduce services and replace full-time workers to part-time ones, which makes the service quality worse. Lastly, in the transferring system, the management system for service quality is not well prepared. There are too much competion because of allowing too many home-help service organizations and care worker academies. The suggestions that this research has found to improve the policy are as follows. ① It is desirable to make the registered clients the service ones as many as possible in the long term perspective. ② The LTCI organization requires more workers and higher professionality. ③ Many elderly people who are not eligible now require connection system to be more served. ④ Management system and service manual for care worker are to be developed. ⑤ Laws related to the service contents and process should be modified, the proportion of client charge needs to adjust. ⑥ Home-help service organization licensed by the LTCI needs to be financially supported publicly. ⑦ Monitoring system to home-help service organization needs to be strengthened. ⑧ Evaluation tools to home-help service organization and workers is required. ⑨ Specification to open the home-help service organization needs to be more strict.