• Journal of Korean Foot and Ankle Society
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• v.26 no.2
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• pp.88-94
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• 2022

Purpose: This study was based on the Korean Foot and Ankle Society (KFAS) member survey and aimed to report the current trends in the epidemiology, diagnosis, and management of acute Achilles tendon rupture (AATR) over the past few decades. Materials and Methods: A web-based questionnaire containing 34 questions was sent to all KFAS members in October 2021. The questions were mainly related to the clinical experience and preferred management of patients with AATR. Answers with a prevalence ≥50% of the respondents were considered a tendency. Results: Seventy-one (12.9%) of the 550 members responded to the survey. The male sex ratio in AATR was answered mean 78%, and the most common age groups were 30~40 years (n=49; 69.0%), and 40~50 years (n=37; 52.1%), in that order. The most common seasons for the occurrence of AATR were spring (37 cases; 52.1%) and autumn (27 cases; 38.0%). Also, sports-related rupture had an average occurrence of 76.2%. The most important clinical factor to determine the type of treatment was the history of previous injuries, and 75.9% of respondents started conservative treatment in the 2010s. The most preferred protocol of conservative treatment was an orthosis capable of ankle range of motion after casting (68.5%), and 53.7% 'satisfied' and 1.9% 'very satisfied' with conservative treatment. The most preferred surgical method was open repair (80.3%), and the Krackow method (60.6%), and 49.3% of treated patients responded 'satisfied' and 45.1% 'very satisfied' with this treatment. Conclusion: This study gives updated information concerning the current trend of epidemiology, diagnosis, and treatment of AATR in Korea. Both consensus and variation in the approach to AATR were identified using this survey study. This study may raise the awareness of various possible approaches toward AATR and should be used to further establish a standard protocol for the management of this injury.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.482-488
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• 2022

In this study, the durability of ultra rapid hardening mortar for sewage pipe was evaluated by type of mortar binder. As a result of analyzing the internal structure for each type of mortar, it was confirmed that Al₂(OH)₃ was generated in the internal structure of the CAC-based mortar, and its corrosion resistance was superior to that of other types of mortar. As a result of the compressive strength test, OPC had the tsmallest strength, followed by CAC100 > CAC100P > CAC80. This trend was similar to the previous study results. Chloride ion penetration resistance and freeze-thaw test showed similar trends. That is, CAC and C12A7 were better than OPC, and CSA was worse than OPC. This is mostly beacuse of cracks caused by expansion of CSA-based mortar. CAC100P mix showed the best chemical resistance. It is thought that this is because the alumina gel formed inside the mortar and the polymer combine to make the internal structure more dense.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.289-298
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• 2023

In this study, the development of a self-healing concrete waterproofing agent was examined, focusing on its manufacturing and waterproofing properties. The optimal ratio using microcapsules for the concrete waterproofing agent was determined through assessments of flow, compressive strength, and permeability conducted during the mortar stage. These findings aimed to provide fundamental data for evaluating the self-healing properties of the concrete waterproofing agent designed for use in concrete structures. The self-healing concrete waterproofing agent was comprised of three types of inorganic materials commonly used for repair purposes. From experimental results, a composition ratio with a high potassium silicate content, referred to as SIM-2, was found suitable. A surfactant mixing ratio of 0.03 % was identified to enhance the dispersibility of the concrete waterproofing agent, while a mixing ratio of 0.2 % distilled water was deemed suitable for viscosity adjustment. For the magnetic self-healing concrete waterproofing agent's healing agent, using microcapsules in the range of 0.5 % to 0.7 % met the KS F 4949 and KS F 4926 standards.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.4
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• pp.203-214
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• 2023

In this study, the physical properties and fracture characteristics according to the tensile load are evaluated on the materials of the polymeric filler and carbon fiber-based composite sleeve technique. The polymeric filler and the composite sleeve technique are applied to areas where the pipe body thickness is reduced due to corrosion in large-diameter water pipes. First, the tensile strength of the polymeric filler was 161.48~240.43 kg_f/cm², and the tensile strength of the polyurea polymeric filler was relatively higher than that of the epoxy. However, the tensile strength of the polymeric filler is relatively very low compared to ductile cast iron pipes(4,300 kg_f/cm²<) or steel pipes(4,100 kg_f/cm²). Second, the tensile strength of glass fiber, which is mainly used in composite sleeves, is 3,887.0 kg_f/cm², and that of carbon fiber is up to 5,922.5 kg_f/cm². The tensile strengths of glass and carbon fiber are higher than ductile cast iron pipe or steel pipe. Third, when reinforcing the hemispherical simulated corrosion shape of the ductile cast iron pipe and the steel pipe with a polymeric filler, there was an effect of increasing the ultimate tensile load by 1.04 to 1.06 times, but the ultimate load was 37.7 to 53.7% compared to the ductile cast iron or steel specimen without corrosion damage. It was found that the effect on the reinforcement of the corrosion damaged part was insignificant. Fourth, the composite sleeve using carbon fiber showed an ultimate load of 1.10(0.61T, 1,821.0 kg_f) and 1.02(0.60T, 2,290.7 kg_f) times higher than the ductile cast iron pipe(1,657.83 kg_f) and steel pipe(2,236.8 kg_f), respectively. When using a composite sleeve such as fiber, the corrosion damage part of large-diameter water pipes can be reinforced with same level as the original pipe, and the supply stability can be secured through accident prevention.

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1339-1349
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• 2023

Purpose To determine the efficacy and safety of iliac branch device (IBD) implantation and to evaluate its limitations based on 7 years of experience in a single center. Materials and Methods This single-center study included patients with bilateral common iliac artery aneurysms (CIAAs). We investigated follow-up CT and reviewed the internal iliac artery (IIA) patency and complications related to IBD. A retrospective analysis was performed and the overall survival rate and freedom from reintervention rate were reported according to the Kaplan-Meier method. Results Of the 38 patients with CIAAs, only 10 (12 CIAAs) were suitable for IBD treatment. Five patients underwent unilateral IBD insertion with contralateral IIA embolization, and three (60%) showed claudication; however, symptoms resolved within 6 months. The 7-year freedom from IBD-related reintervention rate was 77.8%. No procedure-related deaths occurred. Conclusion IBD has good technical success and long-term patency rates; however, anatomical factors frequently limit its application, particularly in Asians. Additionally, unilateral IIA embolization showed relatively mild complications and a good prognosis; therefore, it can be performed safely for anatomically complex aortoiliac aneurysms.

• Journal of architectural history
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• v.20 no.4
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• pp.61-80
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• 2011

This study estimated the prototype of Yangjindang at the time of its foundation by putting together the literature and discovered data and historical research on family related to Sangju Yangjindang, and looked at its architectural characteristics. These are summarized as follows: First, Yangjindang is an office building which was completed in three years [1629] after its start of construction when Keomgan Jojeong was at the age of 72 [1626] in his latter days and it was used for performing ancestral rites for Jojeong's forefathers of the head family of Pungyang Jo by family origin. Yangjindang was founded as a base of utopia for putting ancestral rites & commemoration, harmoniousness of a tribe, and educational idea into practice together with Ojakdang. Such a movement can be judged to interpret and apply the circumstances of the times realistically and flexibly where they tried to pursue the promotion of Confucianism & studies of the proprieties as well as the consciousness of practice, and to bring a tribe into harmony after the war through the retirement of Toegye School. Second, it is located at a topographically ideal spot on the edge of the Jangcheon-a tributary of Nakdong with a good physiology and landscape and its location was also the lot for a house of Jojeong's ancestor, which was burned down by war. Behind such a location and planning of Yangjindang, it is presumed, though not certain that it was modelled after Naeap village at Andong- Jojeong's parents-in-low's home. Third, as for its foundation size, it's a head house as much as about more than 100-kan, and its structure is composed of Samyo, Bonche, and Yangjindang. In addition, arrangements of buildings and its composition system and renovation procedures followed Chu-tzu Garyoe. Composition of Samyo can be restored to Yangjindang, Jugo, Woesammun, and Samyo; however, there has been no case of existence in case of Jugo building composition & arrangement takes on an aspect of a compromise between Gamyojido and Sandangjido of Garoe, which seems to be the result from flexibly interpreting and applying the rituals and studies of the proprieties of Toegye School in keeping with locational topography and realistic circumstances while making it a principle for them to observe by Toegye School. There exists a difference between Bonche and its counterpart of the upper class housing at Sangju district in that Bonche[main building] is a squre-shaped 'Ttuljip' typical of Andong setting a family ancestral ritual as a main function. Fourth, there existed a lot of hardships in raising money to cover repairs in time of doing repairs to this structure after 180 years since its establishment. In case of the repair work on Bonche, the level of renovation was limited to the replacement of old materials for rafters, doorpost, roof members and railings with new materials, together with partial alterations in case of window system. It is estimated that Yangjindang was renovated in 1808, and afterwards it was renamed Okryujeong after being re-built at another site. Through the repairs, the floor was expanded for the clan's meeting, and angle rafters and roof members were mended as well. Especially, the plane and structure of Okryujeong which was re-built at another site are expected to give clues to its restoration due to the resemblance to original appearance of Yangjindang at the time of its renovation in 1808.

• Journal of Periodontal and Implant Science
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• v.30 no.4
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• pp.835-852
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• 2000

The ultimate goal of periodontal therapy is the regeneration of periodontal tissue and repair of function. For more than a decade there have been many efforts to develop materials and methods of treatment to promote periodontal wound healing. Recently many efforts are concentrated on the regeneration potential of material used in oriental medicine. In some in vitro and in vivo experiments, there have been many evidences that these materials have an effect on bone regeneration. The purpose of this study was to evaluate histologically and radiologically in Sprague-Dawley rats the effects of safflower seed extracts on the regeneration of the calvarial defects surgically produced. So in this study, the critical size defects were surgically produced in the calvarial bone of 30 Sprague-Dawley rats using the 8mm trephine bur. The safflower seed extract was applied into the defect of each rat in experimental group, whereas nothing was applied into the defect of each rat in control group. Rats were sacrificed at 2, 4, 8 weeks following operation and histomorphometric and radiodensitometric analysis were performed. 1. The newly formed bone length was $102.91{\pm}22.05$, $178.29{\pm}24.40$ at 2 week in the each control, experimental group, $130.95{\pm}39.24$, $242.62{\pm}50.33$ at 4 week and $181.53{\pm}76.35$, $240.36{\pm}22.00$ at 8 week($unit,{\mu}m$). In the 2, 4 week, there were statistically significant difference between control and experimental group(P<0.05). 2. The newly formed bone area was $2962.06{\pm}1284.48$, $10648.35{\pm}1284.48$ at 2 week, $5103.25{\pm}1375.88$, $9706.78{\pm}1481.81$ at 4 week, $8046.02{\pm}818.99$, $12057.06{\pm}740.47$ at 8 week($unit,{\mu}m^2$). In every week, there were statistically significant difference between control and experimental group(P<0.05). 3. The radiopacity was $14.26{\pm}.33$, $25.47{\pm}4.33$ at 2 week, $20.06{\pm}9.07$, $26.61{\pm}2.78$ at 4 week, $22.99{\pm}3.76$, $27.29{\pm}1.54$ at 8 week(unit, %). In the 2 week, there was statistically significant difference between control and experimental group(P<0.05). In conclusion, the results of the present study suggest that safflower seed extract initially has an effect on the newly formed bone area, length and radiopacity when it is applied to the calvarial defect of Sprague - Dawley rat. Then. the material has an effect on newly formed bone area and length.

• Korean Journal of Heritage: History & Science
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• v.44 no.2
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• pp.76-95
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• 2011

After dismantled, Mireuksajiseoktap(Stone pagoda of Mireuksa Templesite) is being in the stage of restoration design. Now, different ways - producing restoration model, a 3 dimension simulation - have been requested to make more detailed and clearer restoration design prior to confirmation of its restoration design and actual restoration carry-out. This thesis proposes the way to build the detailed model for better restoration plan using extensively-used Reverse Engineering technique and Rapid Prototyping. It also introduces each stage such as a 3-dimension actual measurement, building database, a 3-dimension simulation etc., to build a desirable model. On the top of that, this thesis reveals that after dismantled, MIruksaji stone pagoda's interior and exterior were not constructed into pieces but wholeness, so that its looks can be grasped in more virtually and clearly. Secondly, this thesis makes a 3-dimension study on the 2-dimension design possible by acquiring basic materials about a 3-dimension design. Thirdly, the individual feature of each member like the change of member location can be comprehended, considering comparing analysis and joint condition of member. Lastly, in the structural perspective this thesis can be used as reference materials for structure reinforcement design by grasping destructed aspects of stone pagoda and weak points of the structure. In dismantlement-repair and restoration work of cultural properties that require delicate attention and exactness, there may be evitable errors on time and space in building reinforcement and restoration design based on a 2-dimension plan. Especially, the more complicate and bigger the subject is, the more difficult an analysis about the status quo and its delicate design are. A series of pre-review, based on the 3-dimension data according to actual measurement, can be one of the effective way to minimize the possibility that errors about time - space happen by building more delicate plan and resolving difficulties.

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.212-228
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• 2013

Stone cultural heritages are repaired by the use of metal stiffeners. The problem is that this type of repair has been based on the experience of workers without specific guidelines and has caused various problems. This is to suggest the structural reinforcement and behavioral characteristics of metal rods to minimize the secondary damage of materials and have the specimens tested and verified to establish the guidelines on how to insert metal stiffeners. When only epoxy resin is applied to the cut surface, only 70% of the properties of the parent material are regenerated and it is required to structurally reinforce the metal stiffener for the remaining 30%. The metal rod is under the structural behavior after the brittle failure of stone material and the structural behavior does not occur when the metal stiffener is below 0.251%. When it accounts for over 0.5%, it achieves structural reinforcement, but causes secondary damage of parent materials. The appropriate ratio of metal stiffener for the stone material with the strength of $1,500kgf/cm^2$, therefore, should be between 0.283% and 0.377% of the cross section of attached surface to achieve reversible fracture and ductility behavior. In addition, it is more effective to position the stiffeners at close intervals to achieve the peak stress of metal rod against bending load and inserting the stiffener into the upper secions is not structurally supportive, but would rather cause damage of the parent material. Thus, most stiffeners should be inserted into the lower part and some into the central part to work as a stable tensile material under the load stress. The dispersion effect of metal rods was influenced by the area of reinforcing rods and unrelated to their diameter. However, it ensures stability under the load stress to increase the number of stiffeners considering the cross section adhered when working on large-scale structures. The development length is engineered based upon the diameter of stiffener using the following formula: $l_d=\frac{a_tf_y}{u{\Sigma}_0}$. Also, helically-threaded reinforcing rods should be used to perform the behaviors as a structural material.

• Korean Journal of Heritage: History & Science
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• v.55 no.1
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• pp.243-263
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• 2022

The royal court of Joseon had a tradition of mounting the Irworobongdo, a painting of the sun, the moon and the five sacred peaks, symbols of the king's immortal presence and authority, on a folding screen and placing it in special spaces within the palace that were reserved for the king. While the Irworobongdo is generally accepted as the important ceremonial object of the royal palaces of Joseon, there have been few studies on the various folding screens used in the royal palaces, largely because the official records about such screens do not match the remaining original relics. In this study, the main discussion is focused on the diversity of the shapes and mounting materials of the Irworobongdoused for various ceremonies held in the royal palaces of Joseon based on the Uigwe, the official records of the royal protocols of the Joseon dynasty. The discussion also extends to the theme rarely studied so far, namely the original form of the Irworobongdo and its evolution in the following period. The ceremonial "five peak" folding screens (Obongbyeong) used at a number of important palace buildings, including the crown hall (Jeongjeon), royal funerary hall (Binjeon), spirit hall (Honjeon) and portrait shrine (Jinjeon), differed in shape and size from the folding screens used in royal celebratory events such as banquets, although the paintings themselves and the style of mounting them were essentially the same. The paintings were mounted on screens bordered with green silk and ornamented with floral gilt designs. The folding screens used in royal ceremonies were produced according to strict guidelines that required the ceremonies and mounting materials to be graded on the basis of the status of each screen. It was not until the 1960s that these ceremonial folding screens of the Joseon dynasty, which had been neglected during the period of Japanese colonial rule of Korea, began to undergo conservation treatment provided as part of a heritage preservation program. Unfortunately, many of the screens repaired in this period lost some of their original features - largely due to the use of non-traditional mounting techniques. Considering, however, that significant achievements have since been made in the heritage preservation field based on the use of historical evidence, it is now necessary to systematically use the repair history of the information about the remaining royal ceremonial folding screens to ensure that they are preserved and managed more effectively in the future.