• Journal of the Korea Furniture Society
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• v.18 no.1
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• pp.39-46
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• 2007

This study was carried out to investigate the wood properties for efficient utilization of warm temperate tree species of Quercus acuta Thunb. grown in Korea. Fundamental wood properties in the anatomical, physical, mechanical and chemical characteristics were examined. Quercus acuta Thunb. is a radial-porous, straight grained and fine textured wood. The heartwood is not clearly distinguished from the sapwood. In physical properties, it has a high oven-dry specific gravity of $0.85{\pm}0.02$, and high shrinkage from green to air-dried condition of $7.05{\pm}0.52%$ in radial and $11.13{\pm}0.48%$ in tangential direction. Mechanical properties determined are strong with the MOR of $1,065{\pm}90kgf/cm^2$, and tensile strength parallel to grain of $1,490{\pm}258kgf/cm^2$ and shear strength of $175{\pm}13kgf/cm^2$. Also, this wood has high extractive contents: 11.11% for cold and 13.51% for hot water.

• Journal of Korean Physical Therapy Science
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• v.11 no.3
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• pp.49-59
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• 2004

The purpose of this study was carried out to rind out the prevalence of occupational musculoskeletal disorders among workers in manufacturing industries, so that the result could provide basic data necessary to prevent musculoskeletal disorders. Information on general characteristics, occupational characteristics, and musculoskeletal symptoms were obtained by a self-administered questionnaire between October and November in 2002, from 345 workers in Kim-hae and Ulsan, Kyung-nam province. The data were analyzed for chi-square test by using SPSS NVIN 10.0 program. The results are as follows: According to the self-reports, among musculoskeletal symptoms complain on shoulders are topping for 50.4%, low back is followed for 40.6%, leg/foot 35.7%, neck 34.5%, wrist/hand/finger 30.1%, and arm 24.3%. According to occupational characteristics prevalence by anatomical site, about neck pains 119 subject, occupational satisfaction is 62,6% in moderate group, work shift is 71.8% in no work shift group, each significant high. Symptom complain rate of 104 patients who complained on wrist, hand and finger pain is significantly related that 36.5% below 5 years and 36.5% above 15 years have been worked group. And each of them are significantly related 77.9% in labor workers group, 70% in no work shift group, 54.8% in frequent transfer group. Among 140 subjects who have back pain, that is significationtly reported on 37.1% below 5 years and 37.9% above 15 years and 60.0% moderate satisfied occupation group have been worked group. Therefore, some efforts should be proceeded such as improvement of working condition, flexibility for changing work, more pleasant and better working environment, and etc.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.659-665
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• 2014

Wood properties are affected by environmental factors such as soil and climate change. There were close relationships between mechanical properties and stand characteristics for Quercus serrata stands in Gyeongsangnam-do Province, Jeollanam-do Province and Je-ju island. Both compression and shear strengths of woods showed a negative correlation with diameter at breast height (DBH) and the number of tree per hector, while they are positively related with with tree age, altitude, and drainage. The annual ring width was also negatively correlated with tree age, altitude, drainage, DBH, and tree height. However, anatomical characteristics of wood did not show much variation depending on the provincial regions. These results brought a conclusion that Quercus serrata in southern region could be useful forest resources for the utilization of wood.

• Progress in Medical Physics
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• v.32 no.1
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• pp.1-17
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• 2021

The evolution of X-ray computed tomography (CT) has been based on the discovery of X-rays, the inception of the Radon transform, and the development of X-ray digital data acquisition systems and computer technology. Unlike conventional X-ray imaging (general radiography), CT reconstructs cross-sectional anatomical images of the internal structures according to X-ray attenuation coefficients (approximate tissue density) for almost every region in the body. This article reviews the essential physical principles and technical aspects of the CT scanner, including several notable evolutions in CT technology that resulted in the emergence of helical, multidetector, cone beam, portable, dual-energy, and phase-contrast CT, in integrated imaging modalities, such as positron-emission-tomography-CT and single-photon-emission-computed-tomography-CT, and in clinical applications, including image acquisition parameters, CT angiography, image adjustment, versatile image visualizations, volumetric/surface rendering on a computer workstation, radiation treatment planning, and target localization in radiotherapy. The understanding of CT characteristics will provide more effective and accurate patient care in the fields of diagnostics and radiotherapy, and can lead to the improvement of image quality and the optimization of exposure doses.

• Journal of the Korean Wood Science and Technology
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• v.52 no.1
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• pp.87-100
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• 2024

Wood has different properties depending on the species or growth area. Therefore, in order to use wood efficiently, it is necessary to have a proper understanding of the characteristics of wood depending on the species and the appropriate use for them. In particular, in order to effectively use more than 1,000 species of woody plants in South Korea as wood, it is necessary to evaluate the characteristics of various Korean domestic woods and make a database of them. In this study, the anatomical properties (length and width of tracheid, cell wall thickness), physical properties (specific gravity and shrinkage), mechanical properties (bending strength, compressive strength, tensile strength, shear strength, hardness), and chemical composition (ash, extract, lignin, total sugar content) of Korean red pine which was grown in Pyeongchang-gun, Gangwon-do, South Korea were evaluated.

• Journal of the Korean Wood Science and Technology
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• v.25 no.2
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• pp.117-126
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• 1997

In fast grown softwood, there are very large changes in material properties going outward from the pith to bark such as anatomical, physical and mechanical characteristics. Some of variations in anatomical properties with annual ring were then examined from Pinus koraiensis, Larix leptolepis, and Chamaecyparis obtusa, which are major softwoods of plantation in Korea. The large variations of annual ring width during young age of tree tended to stabilize after 25year through the transitional period in 17~23year. The ring density was 1.5~2.4 in 1~10year period, and 3.5~6.3 in 30~35year period, in which juvenile and mature wood were certainly assumed to be formed, respectively. Variations of tracheid length showed functional relationships with annual rings as logarithm. Demarcation between juvenile wood and mature wood could be 16~19year, which was determined from increase rate of tracheid length of 0.2%. Cell wall thickness increased with increase of annual ring even though large variations were observed as well. Variations of cell wall thickness within species were pronounced in latewood than earlywood. The increase of cell wall thickness from juvenile wood to mature wood was predominant in Larix leptolepis as 2.0times, and least in Chamaecyparis obtusa as 1.1 times. Cell diameters showed trends of increase during young age of 1~15year, and consistent afterward. The variations of cell diameter between radial and tangential direction were greater in latewood, and most pronounced in Chamaecyparis obtusa.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.1
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• pp.47-56
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• 2011

This study was carried out to investigate the characteristics of the Hanji which had been used for movable types printing volumes of the Joseon Dynasty. A total 29 volumes which had printed with metal and wooden movable types, were examined on the physical properties, fiber morphology, and color reactions. The grammage of all of the Hanji which had been used for movable types printing volumes were $13.10-51.65g/m^2$ and on the average was $25g/m^2$. The apparent density of the Hanji was $0.23-1.65g/cm^3$ and on the average was $0.4g/cm^3$. In almost all movable types printing volumes, the Hanji had undergone Dochim which is a processing of printability improvement. Through the examination on fiber morphology and color reactions, Hanji was investigated into that all of those were made from paper mulberry bast fiber.

• Journal of the Korea Furniture Society
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• v.11 no.1
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• pp.13-23
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• 2000

This study was carried out to investigate the wood properties for development the proper uses of lesser-known tree species. The tested species are Kebambang(Pentace sp.), Bawang-bawang(Dysoxylum alliaceum Bl .), Garu buaya( Gonystylus brunescens A. Shaw)grown in Indonesia. fundamental wood properties such as anatomical, physical, mechanical and chemical properties and characteristics related to wood processing were examined. The results are summarized as follows : The woods of these species are diffuse porous, coarse textured, and interlocked grained. The heartwood of Kebambang is distinguished clearly to the sapwood, but the heartwood of other species are not distinguished clearly to the softwood. The woods of Kebambang and Bawang-bawang have the moderate weight density and the low strength properties, but Garu buaya has the high weight density and the high strength properties. The woods of these species has high shrinkage. The sawing characteristics of Kebambang are excellent but the other species are moderate. The machining characteristics by planer and drying characteristics of these species are moderate. These woods has poor characteristics in bending processing and decay durability. The wood of Bawang-bawang has high content of the extractives and lignin.

• Journal of the Korea Furniture Society
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• v.11 no.2
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• pp.25-35
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• 2000

This study was carried out to investigate the wood properties for development the proper uses of lesser-known tree species. The tested species are Tamiang(Hydnocarpus woodii) Bangelem (Strombosia zeylanica) and Kamasulan(Anisophyllea ferruginea) grown in Indonesia. fundamental wood properties such as anatomical, physical and chemical properties and characteristics related to wood processing were examined. The results are summarized as follows : These species are diffuse porous, interlocked grained and coarse textured wood. Exceptionally, texture of Tamiang is fine. The heartwoods of these species are not distinguished clearly to the sapwoods. These species have high specific gravity, high shrinkage, and excellent strength properties. However, Tamiang has moderate specific gravity. Sawing characteristics are poor for these species except Tamiang. Sawing characteristics is moderate for Tamiang. Drying characteristics are moderate for Tamiang and Bangelem, and Poor for Kamasulan. The surfacing characteristics by planer are moderate f3r all these species. Bending property and durability are poor. Ash content is low in Bangelem.

• Physical Therapy Korea
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• v.29 no.3
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• pp.241-248
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• 2022

Background: The PyeongChang 2018 Winter Paralympic Games (WPG) being one of the most successful Paralympic Games (PG) in modern athletic world history, hosted the largest number of elite athletes representing 49 National Paralympic Committees (NPCs). Objects: The present investigation highlighted the demographic and clinical characteristics of injured athletes and non-athletes and the physiotherapy services provided during the PyeongChang 2018 WPG. Methods: Prospective descriptive epidemiology study, in which the study group comprised of 201 participants (51 athletes and 150 non-athletes) who were admitted to and utilized the polyclinic physiotherapy service of 2018 PyeongChang WPG in Physiotherapy Department of Paralympic Village from March 1, 2018 to March 20, 2018. Results: Qualitative frequency analysis of injury type demonstrated highest number of chronic injuries (51%, n = 100) in athletes and non-athletes. Anatomical injury site analysis revealed that the spine and shoulder areas were affected with equal frequency for athletes (54.9%, n = 14), whereas for non-athletes, the frequencies of spine and shoulder area injuries were 36.7% (n = 55) and 26% (n = 39), respectively. The Pyeongchang WPG showed a high rate of athletes visiting the physiotherapy service during the pre-competition period (33.3%, n = 50), which may have led to smaller incidence rate of traumatic injury. The physiotherapy treatment service analysis demonstrated that manual therapy (35.4%, n = 230) was most commonly utilized, followed by transcutaneous electrical nerve stimulation/interference current therapy (TENS/ICT), therapeutic massage and therapeutic exercise. Conclusion: We established the importance of prophylactic and preventive physiotherapy services to reduce the risk of sports injuries during WPG.