• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.312-320
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• 2019

One of the fastest growing segments of implant dentistry is the utilization of computed tomography (CT) scan data and treatment planning software in conjunction with guided surgery for implant reconstruction cases. Computer assisted planning systems and associated surgical templates have established a predictable, esthetic, functional technique for placing and restoring implants. Especially, a philosophy of restoratively driven implant placement has been generally adopted. Recently, a variety of commercial dental fields have released their scanning and fabricating protocols and methods for restorations. This process is still being investigated and developed for the most precise and predictable outcome. This case report describes a female patient who wanted dental implants in fully edentulous areas. Restoratively driven implant placements were performed with surgical guide and the patient was fully satisfied with the clinical results, and at 5-year post restorative follow-up assessment, both implant and prosthesis were proved clinical success.

• Conservation Science in Museum
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• v.25
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• pp.1-8
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• 2021

This study investigated White Porcelain Water Dropper with Openwork Lotus Scroll Design and Eight Trigram Design in Cobalt-blue Underglaze (hereinafter, the "water dropper") in the collection of the National Museum of Korea using computed tomography (CT). A replica was produced to examine both the structure and its original production method. The CT scanning identified no joint lines or pores in the clay, which suggests that the body (the lower part of the water dropper) was shaped in a single piece using a mold and was then matched with a mold-formed lid (the upper part of the water dropper). The inner container of the body portion was roughly trimmed with a bamboo knife so that its upper surface could be securely attached to the bottom of the lid and prevent any leakage in the joined surface. It appears that the inner container for storing water was made first in a cylindrical shape that met the unit of quantity used at the time and could be easily formed by molding. It was transformed into a trapezoid shape during the process of combining it with the lid. A cylindrical inner container was reproduced using silicon 3D printing to compare its capacity with that of the original inner container. The comparison revealed that the reproduced container had a capacity of 152.5㎖, whereas the original container holds approximately 168.6㎖, a figure similar to three hop (around 174㎖) in Joseon-period units of quantity. Since the capacity of the cylindrical inner container corresponds to a known measure from the late Joseon dynasty, it is likely that the water dropper was originally produced to contain a cylindrical inner container.

• Journal of Conservation Science
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• v.38 no.3
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• pp.234-242
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• 2022

The study aimed to investigate the split casting method based on the recreation of the iron-seated Buddha (ISB) statue (number 1971) in the Chuncheon Museum. The statue was designed using three-dimensional scan data and reduced to half-size. Using the existing research results, the ISB statue was created by mold production and split casting. The mold was prepared by mixing sand and clay at a ratio of 3:4 and 1:3 on the outside and inside, respectively, and then casting was done. Various casting defects were observed in the ISB casting and similar shapes were seen. The casting defects included veining or finning, misrun, open or external shrinkage, surface or subsurface blowholes, surface pinholes, and shift. The microstructures were identified as branch-shaped dendrite and pearlite organizations, and black graphite was observed between the cementite organizations. The study findings may be relevant in exploring traditional casting and manufacturing techniques of ISB and may aid in the production of the original form of ISB.

• Clean Technology
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• v.29 no.4
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• pp.237-243
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• 2023

Aerogel is the most excellent insulation material known to date, but it is inflexible and has very low strength. A blanket containing aerogel in a nonwoven fabric or fiber is currently the most practical form. However, aerogel blankets are not yet widely used because they cannot avoid dust generation when handled, lack flexibility, and can possibly deform. In this study, vacuum treatment, surface treatment, and composite materialization technology were applied to solve this problem, and some prototypes were also made. If an aerogel blanket is wrapped in an aluminum sheet, sealed at the four ends, and vacuumed, it can become a material with better insulation than the blanket itself. An aerogel molded body can be made by coating the aerogel blanket with resin and treating the surface. If the aerogel blanket is multi-packed and laminated with resin or fiber in multiple layers to make it a composite material, it can be used as a flexible insulation material. In particular, this composite material, which utilizes a Teflon membrane with controlled pores, is breathable and waterproof, so it can be used for clothing. Prototypes of insoles for winter boots and outdoor roll mats were also produced using aerogel blanket resin and fiber composites. These prototypes showed low thermal conductivity of less than 20 mW m^-1K^-1, with good flexibility and durability.

• Journal of Korean Society of Forest Science
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• v.113 no.2
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• pp.198-209
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• 2024

This study aimed to investigate the impact of light intensity, manipulated through different shading levels, on the growth and physiological responses of Thermopsis lupinoides. To assess the effects of shading treatments, we examined leaf mass per area, chlorophyll content, chlorophyll fluorescence response, and photosynthetic characteristics. T. lupinoidesexhibited adaptive responses under low light conditions (50% shading), showing increased leaf area and decreased leaf mass per area as shading levels increased. These changes indicate morpho-physiological adaptations to reduced light availability. At 50% shading, the physiological and ecological responses were favorable, with optimal photosynthetic functions including chlorophyll content, photosynthesis saturation point, photosynthetic rate, carbon fixation efficiency, stomatal conductance, transpiration rate, and water use efficiency. However, at 95% shading, the essential light conditions for growth were not met, significantly impairing photosynthetic functions. Consequently, 50% shading was determined to be the most optimal condition for T. lupinoides growth. These findings provide valuable insights for effective ex-situconservation practices and site selection for T. lupinoides, serving as foundational data for habitat restoration efforts.

• Composites Research
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• v.37 no.3
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• pp.162-169
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• 2024

In this study, PAN(polyacrylonitrile)-based precursor fibers were produced through a wet-spinning process, and their morphologies and graphitization behavior were investigated in the presence of two graphitization catalysts (Ca, Ni). The graphitization catalysts were introduced into the formed pores during hot-water stretching of wet-spun PAN-based precursor fibers. The catalytic effects of graphitization catalysts were examined through crystal structure and Raman analysis. At a relatively low temperature of 1500℃, the graphitization was not significantly affected, whereas at a high temperature of 2400℃, the obtained I_D/I_G value of graphite fiber (GF-Ni100) was decreased by about twice (~0.28) compared to the untreated fibers (GF-AS~0.54). By comparing the I_D/I_G values (GF-Ca100~0.42: GF-Ni100~0.28) of Ca and Ni graphitization catalyst, it was found that the degree of graphitization of Ni graphitization catalyst showed higher influence than that of Ca graphitization catalyst. Moreover, 2D band was also observed, indicating that the graphite plane structures composed of multiple layers were developed. XRD results confirmed that the crystal inter-planar distance (d₀₀₂) of the graphite crystal was slightly decreased after the treatment with the graphitization catalyst, But, the crystal size of Ca-treated graphite fiber (GF-Ca100) was increased by up to ~5 nm.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.393-405
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• 2021

With increasing anthropogenic emission sources, air pollutants are emerging as a severe environmental problem worldwide. Accordingly, the importance of landscape trees is emerging as a potential solution to reduce air pollutants, especially in urban areas. This study quantified and compared NO₂ and SO₂ reduction abilities of ten major landscape tree species and analyzed the relationship between reduction ability and physiological and morphological characteristics. The results showed NO₂ reduction per leaf area was greatest in Cornus officinalis (19.81 ± 3.84 ng cm^-2 hr^-1) and lowest in Pinus strobus (1.51 ± 0.81 ng cm^-2 hr^-1). In addition, NO₂ reduction by broadleaf species (14.72 ± 1.32 ng cm^-2 hr^-1) was 3.1-times greater than needleleaf species (4.68 ± 1.26 ng cm^-2hr^-1; P < 0.001). Further, SO₂ reduction per leaf area was greatest in Zelkova serrata (70.04 ± 7.74 ng cm^-2 hr^-1) and lowest in Pinus strobus (4.79 ± 1.02 ng cm^-2 hr^-1). Similarly, SO₂ reduction by broadleaf species (44.21 ± 5.01 ng cm^-2 hr^-1) was 3.9-times greater than needleleaf species (11.47 ± 3.03 ng cm^-2 hr^-1; P < 0.001). Correlation analysis revealed differences in NO₂ reduction was best explained by chlorophyll b content (R² = 0.671, P = 0.003) and SO₂ reduction was best described by SLA and length of margin per leaf area (R² = 0.456, P = 0.032 and R² = 0.437, P = 0.001, R² = 0.872, P < 0.001, respectively). In summary, the ability of trees to reduce air pollutants was related to photosynthesis, evapotranspiration, stomatal conductance, and leaf thickness. These findings highlight effective reduction of air pollutants by landscaping trees requires comprehensively analyzing physiological and morphological species characteristics.

• Korean Journal of Plant Resources
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• v.36 no.2
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• pp.172-180
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• 2023

In the current study, four groups; control, 500, 1000, and 2000 mg/L, were treated to investigate the effects of physiological and growth characteristics on Machilus thunbergii under various fertilization levels. As a result of the physiological response to the fertilization treatment, the fertilized group demonstrated relatively higher levels of A, ITE, WUEi, V_camx, PI_abs, and SFI_abs in comparison to the control. The best photosynthetic mechanism was most clearly seen at 1000 mg/L, which involved gas exchange through active stomatal opening and closing. For a productive photosynthetic mechanism. As seen in the growth response of M. thunbergii to fertilization treatment, the fertilized group has significantly higher height, DRC, leaf dry weight, stem dry weight, total dry weight, LWR, and SWR than the control group. A healthy seedling quality index was particularly evident at 1000 mg/L, and other growth indicators were also at a decent level. 500 mg /L also demonstrated growth characteristics that were comparable to those at 1000 mg/L. As a result, M. thunbergii featured the best physiological and growth characteristics in response to the fertilization treatment at 1000 mg/L, and 500 mg/L also showed a similar trend, which is considered to be a good option from an economical perspective.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.20-30
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• 1979

The purpose of present study is to analyze the genetic variation of natural stand of Pinus densiflora. In 1976 following after the seletion of 1974 and 1975, twenty trees from each of three natural populations of the species were selected and seeds were collected, and the locations and conditions of populations are presented in table 1, 2 and figure 1. Some morphological traits of the populations were already detailed in our fifth report of this series. The morphological traits of cone, seed and seed-wing, and also the growth performances and needle characters of the seedling were observed in the present study according to the previous methods. The results obtained are summarized as follows; 1. The meteorological data obtained by averaging the records of 30 year period(1931~1960) measured from the nearest meteorological station to each population are shown in fig. 2, 3, 4. The distributional patterns of investigated climate factors are generally considered to be similar among the locations. However, the precipitation density during growing season and the air temperature during dormant season on Samchuk area (Pop. 9) were quite different from those of the other areas. 2. The measurements of fresh cone weight, length, diameter and cone index (i.e.: length to diameter ratio) are presented in table 7. As shown in table 7, all these traits except for cone diameter seem to be not significant in population and to be highly significant in family differences within population. 3. The morohological traits of seed and seed-wing are detailed in table 8, 9, and highly significant differences are recognized among the populations and the families within population in seed weight, seed length, seed thickness but not among the populations in the other observed traits. The values of correlation between the characteristics of cone and seed are presented in table 12. As shown, the correlation between cone length and seed wing length, between seed wing width and seed width were significantly positive in population 8 and 9 but in population 7. The positive correlations between seed length and seed width were calculated in all populations studied 4. Significant statistical differences among populations and families within population are observed in the growth performances of 1-0 seedling height of these progenies. But the differences in 1-1 seedling height and root collar diameter are shown only among familes within population. As shown in table 13, the most parts of correlations are not significant statistically between the growth performances of seedling and the seed characters. 5. As shown in table 15, statistical differences are considered to be significant among the populations in stomata row on both sides of the needle but not in serration density. The correlations between progenies and parents are not generally observed in the investigated traits of needle as shown in table 16.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.3
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• pp.26-38
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• 2011

The purpose of this study was to analyze the commemoration culture of Vietnam War Memorials (VWM) in Vietnam. Through site survey, the researcher selected 23 VWM in Vietnam and analyzed 5 categories: memorial type, design concept and narratives, location and spatial form, landscape elements, and content expressed in landscape details. The results are as follows: 1. Because of the long, drawn out Vietnam War, which lasted from 1955 to 1975, VWM were divided into 10 types mainly as soldier cemeteries based on a traditional memorial style, battlefields and places of tragedies considering sense of place, war museums representing victory and atrocity in war, and peace parks promoting reconciliation and peacemaking. 2. The analysis revealed that the main concepts and narratives of VWM were to value the victims of the Vietnam War, remember soldiers' contributions, highlight the victory in war and resistance to the United States, and express a sense of place. Peacemaking applied only to My Lai Peace Park and Han-Viet Hoa Binh Cong Vien, built by international cooperation. 3. Cemeteries and appreciation memorials were designed to follow a traditional memorial space form that highly regard both axis and symmetry. The design concept at battlefields and places where tragedies occurred depended mainly upon a sense of place and used symbolic landscape elements to compensate for the undefined concept. 4. Sculptures and towers were mainly used to highlight war victory and resistance as the representative style of a Socialist country, weapons and pictures exhibited in war museums and battlefield showed the reality and strain of war. Symbolic elements of Buddhism and Confucianism were often introduced as a way to venerate the memory of deceased persons. 5. The state and heroic actions in the Vietnam War were realistically depicted on sculptures and walls. Also, the symbolic phrase, 'TO-QUOC-GUI-CONG' meaning 'our country remember your achievement', were written on the memorial tower and 'Quagmiire' was used to metaphorically represent the difficulties faced by the U.S. military on battlefields during the war and the uncertainly that pervaded U.S. society in those days. 6. In VWM, ideologies like nationalism, patriotism, socialism, capitalism were mixed and traditional cultures like Buddhism, Confucianism, Taoism were inherent. Differing from their Confucianism culture, war heroes, particularly including women, were often described by sculpture, monument, and pictures and the conflict in and outside the country regarding the Vietnam War was shown. Further study will be required to analyze design characteristics of VWM in the u.s. and to understand the difference in commemoration cultures between Vietnam and the U.S.