• Structural Engineering and Mechanics
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• v.22 no.2
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• pp.131-150
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• 2006

Exact analytical solutions for in-plane static problems of planar curved beams with variable curvatures and variable cross-sections are derived by using the initial value method. The governing equations include the axial extension and shear deformation effects. The fundamental matrix required by the initial value method is obtained analytically. Then, the displacements, slopes and stress resultants are found analytically along the beam axis by using the fundamental matrix. The results are given in analytical forms. In order to show the advantages of the method, some examples are solved and the results are compared with the existing results in the literature. One of the advantages of the proposed method is that the high degree of statically indeterminacy adds no extra difficulty to the solution. For some examples, the deformed shape along the beam axis is determined and plotted and also the slope and stress resultants are given in tables.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.3
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• pp.617-623
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• 1990

Cracks present in pressure vessels have been reported to be mostly semi-elliptic surface cracks. The fatigue crack growth rates(FCGR) of surface cracks in the pressure vessel materials, API5A-K55 and SPV 500, used in this study were showed to be different depending on the direction of propagation of the surface crack. An equation for the prediction of the shape change of the surface crack was obtained by combining the Paris' relations for each direction of surface crack extension and agreed well with the experimental data. And also FGGR in both materials were evaluated and prediction of the shape change of surface crack were made using averaged stress intensity factor.

• 한국가시화정보학회:학술대회논문집
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• 2004.12a
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• pp.15-23
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• 2004

The present study is aimed to achieve dynamic visualization from the in-house 3-D stereoscopic PIV to represent quantitative flow information such as time-resolved 3-D velocity distribution, vorticity, turbulent intensity or Reynolds stresses and so on. One of the application of the present study is Leading edge extension(LEX) flow appearing on modern delta wing aircraft. The other is mixing flow in stirring tank used in industry field. LEX in a highly swept shape applied to a delta wing features the modern air-fighters. The LEX vortices generated upon the upper surface of the wing at high angle of attack enhance the lift force of the delta wing by way of increased negative suction pressure over the surfaces. The present method resolves also the complicated flow patterns of two type impellers rotating in stirring vessel. Flow quantities such as three velocity vector components, vorticity and other flow information can be easily visualized via the 3D time-resolved post-processing visualization. And it makes the easy understanding of the unsteady flow characteristics of the typical industrial mixers.

• The Plant Pathology Journal
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• v.19 no.2
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• pp.79-84
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• 2003

Sclerotinia rot occurred severely on some vegetable crops grown in Namyangju, Yangpyung, and Yangiu areas in Korea in 2001-2002. The crops infected with Scterotinia sp. were Adenophora remotiflora, Armoracia lapathfolia, Angelica acutiloba, Angelica archangelica, Anthriscus sylvestris, Aster tataricus, Beta vulgaris var. cicla, Brassica campestris var. marinosa, Brassica juncea var. laciniata, Chicholium intybus, Lactuca indica var. dracoglossa, Lactuca sativa var. oak-leaf, Petroselinum crispum, and Phyteuma japonicum. The fungus associated with the disease was identified as Sclerotinia sclerotiorum, based on the morphological characteristics of the pathogen. The symptoms were water-soaked spots that enlarged later and became a watery soft rot. Infected parts became yellow and then turned brown, followed by death of the whole plant. White mycelia developed on the upper petioles and leaves and on the soil where these plant parts lay. Then black sclerotia in variable size and shape formed from the mycelial mass. Pathogenicity of the fungus was proven by artificially inoculating each crop. This is the first report of Sclerotinia rot on the listed vegetable crops in Korea.

• Mycobiology
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• v.32 no.2
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• pp.95-97
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• 2004

In July 2002, a destructive stem rot of tawny daylily(Hemerocallis fulva) was occurred sporadically in exhibition farm of Gyeongsangnam-do Agricultural Research and Extension Services located in Hamyang-gun, Korea. The fungus also caused collar and crown rot, and systemic wilt or blight of whole plant. White mycelium spread over stems and petioles of infected plants and sclerotia were formed on the old lesions and near the soil surface. The optimum temperature for mycelial growth and scierotial formations was $30^{\circ}C$ on PDA. The mycelial width ranged $4.2{\sim}10.4{\mu}m$ and the color was white, usually many narrow mycelial strand grew in the aerial mycelium and formed clamp connection. The shape of sclerotia was spherical and $1.0{\sim}3.2$ mm in diameter. The fungus was isolated repeatedly from the infected tissues and confirmed its pathogenicity to Hemerocallis fulva and identified as Sclerotium rolfsii. This is the first report on the stem rot of H. fulva caused by S. rolfsii in Korea.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.7 no.1
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• pp.85-89
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• 2007

Many authors considered the computational aspect of sup-min convolution when applied to weighted average operations. They used a computational algorithm based on a-cut representation of fuzzy sets, nonlinear programming implementation of the extension principle, and interval analysis. It is well known that $T_W$(the weakest t-norm)-based addition and multiplication preserve the shape of L-R type fuzzy numbers. In this paper, we consider the computational aspect of the extension principle by the use of $T_W$ when the principle is applied to fuzzy weighted average operations. We give the exact solution for the case where variables and coefficients are L-L fuzzy numbers without programming or the aid of computer resources.

• Journal of Agricultural Extension & Community Development
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• v.17 no.2
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• pp.305-326
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• 2010

This study aimed to investigate couple relationship and related variables of women immigrants. Especially, the study focused on curve term between couple relationship and related variables. The data were collected from a sample of 346 women immigrants living in S city, Chungnam province. First, the study indicated that there was some curve relationship between couple satisfaction and period of residence in Korea. Namely, the couple satisfaction of women immigrants was likely to decrease at the early period of residence, but the longer the period of residence was, the higher the couple satisfaction was. Second, the result revealed that there was no significant relationship between couple satisfaction and level of Korean proficiency. Third, there was some curve relationship between couple satisfaction and satisfaction of life. The couple satisfaction was likely to increase in a shape of curve according to the increase of life satisfaction.

• Journal of Agricultural Extension & Community Development
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• v.5 no.2
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• pp.153-164
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• 1998

Rural Environmental Planning (REP) is a method used by citizens in small towns and rural areas to plan their own future. REP assumes that the primary social value of rural people is to enhance a community's longterm viability by respecting the carrying capacity of the natural environment. REP derives its strength from the direct participation of those people affected by a plan. They determine its goals, shape its content, and implement its components. And both the rural environmental planner and the citizens involved in planning in their community must have a working knowledge of the legal framework of planning. In the results, REP reduces the cost of planning by drawing public agencies, not-for-profit organizations, volunteers from the private sector, and all vital resources available to rural people when they plan for their future.

• The Plant Pathology Journal
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• v.15 no.5
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• pp.308-310
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• 1999

A fungus associated with gray blight on tea plant (Camellia sinensis) was identifed as Pestalotiopsis theae based on the mycological characteristics. Mycelial growth on potato dextrose agar and size and shape of conidia of P. theae were similar to those of P. longiseta, but P. theae was different from P. longiseta in the color of three median cells and the number of apical appendages. Artificial inoculation of conidial suspension or mycelial mats on the wounded leaves and shoots of healthy plants induced the same disease, respectively. The Korean native variety was relatively. The Korean native variety was relatively more resistat to P. theae than a Japanese variety‘Yabukita’which has bee recently introduced and planted in large areas of southern parts of Korea. Here, we report the report the first record of gary blight caused by P. theae on tea plant in Korea.

• Journal of Agricultural Extension & Community Development
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• v.30 no.4
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• pp.187-197
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• 2023

The study aims to identify factors related to landscape structure and socioeconomic characteristics that influence adults' physical activity and health. The study analyzes data from 148,643 respondents from the Korea Community Health Survey conducted in 2021. The study measures various factors, including the frequency of physical activity, stress, depression, and landscape metrics of forest patches. Hierarchical multiple regression analysis was used, controlling for socio-demographic characteristics. Larger forest patches and more irregular shapes are associated with higher levels of physical activity among adults. The percentage and area of the forest patch are associated with fewer mental health complaints. Configuration-related landscape metrics such as shape or arrangement of the forest patch did not show a significant association with physical activity. Overall, the study provides insights into how specific characteristics of forest patches in urban areas may influence physical activity and mental health among adults. It emphasizes the importance of green spaces and their potential positive effects on both physical and mental well-being.