• Clinical and Experimental Pediatrics
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• v.50 no.12
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• pp.1173-1179
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• 2007

The diagnosis of juvenile rheumatoid arthritis (JRA) is based on patient's age at disease onset, symptom duration, gender, and clinical manifestations. JRA is of unknown origin, begins under the age of 16, and persists for a minimum of 6 weeks. JRA is categorized into three principal types, systemic, oligoarticular and polyarticular. Infection, other connective tissue diseases, malignancy, trauma, and immunodeficiency are discussed as differential diagnoses for JRA. Because of joint damage, focusing on early diagnosis and intervention, a vigorous initial therapeutic approach must be taken in patients who have poor prognostic factors. A multidisciplinary team approach is also important for the care of patients with JRA.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.728-731
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• 1995

Miniaturzed specimen technology permits mechanical bechanical behavior to be determined using a minimum volume of material. because it is almost impossible to sample the conventional specimen for the fracture toughness test without damage to the rotor. In addition, it is different to collect a large amount of actual turbine rotor steels. Hence seven kinds of specimen with different degradation levels were prepared by isothermal aging heat treatment at 630 .deg. C. Test material was 1Cr-1Mo-0.25V steel which was widely used for turbine rotor material. The relation between fracture toughness and DBTT was investigated The characteristics of minaturized impact speciments technique was discussed. Finally, the estimating method of fracture toughness using a single impact specimen was introduced.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.69-76
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• 2002

Mustard aphid, Lipaphis erysimi(Kalt.) plays a key role in determining the productivity of rapeseed-mustard. This pest alone attributes 30-70% losses in yield potential in different agro climatic zones with a mean loss of 54.2% in India. Considering the extent of damage caused by the pest, the present experiment was conducted at Pulses and Oilseeds Research Station during 1992-93 to 1994-95 to study the migratory nature of mustard aphid by trapping them in yellow colour pan tray and their simultaneous growth and development on three different genotypes. The temperature during noon hours is the predominant factor to govern the appearance of alate mustard aphid in rapeseed-mustard field. Stepwise regression analysis revealed that temperature and relative humidity played an important role for its development. The variety RW white flower glossy stem harboured minimum number of aphid in comparison to other two varieties B 9 and T6342. The population reached a peak of 61.28 aphids/10 cm central twig during $6^{th}$ standard week irrespective of varieties.

• Structural Engineering and Mechanics
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• v.25 no.1
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• pp.21-37
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• 2007

In this study a stochastic approach for linear viscous dampers design adopted for seismic protection of buildings is developed. Devices optimal placement into the main structure and their mechanical parameters are attained by means of a reliability-based optimum design criterion, in which an objective function (O.F.) is minimized, subject to a stochastic constraint. The seismic input is modelled by a non stationary modulated Kanai Tajimi filtered stochastic process. Building is represented by means of a plane shear type frame model. The selected criterion for the optimization searches the minimum of the O.F., here assumed to be the cost of the seismic protection, i.e., assumed proportional to the sum of added dampings of each device. The stochastic constraint limits a suitable approximated measure of the structure failure probability, here associated to the maximum interstorey drift crossing over a given threshold limit, related, according with modern Technical Codes, to the required damage control.

• Coupled systems mechanics
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• v.7 no.3
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• pp.333-351
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• 2018

In the present paper, the behavior of the Karaj double curvature arch dam is studied focusing on the effects of structural nonlinearity on the responses of the dam body when an underwater explosion occurred in the reservoir medium. The explosive sources are located at different distances from the dam and the effects of the cavitation and the initial shock wave of the explosion are considered. Different amount of TNT are considered. Two different linear and nonlinear behavior are assumed in the analysis and the dam body is assumed with and without contraction joints. Radial, tangential and vertical displacements of the dam crest are obtained. Moreover, maximum and minimum principal stress distributions are plotted. Based on the results, the dam body responses are sensitive to the insertion of joints and constitutive model considered for the dam body.

• International Journal of Control, Automation, and Systems
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• v.4 no.1
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• pp.10-16
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• 2006

In this paper, moving a fragile object from an initial point to a specific location in the minimum time without damage is studied. In order to achieve this goal, initially, the maximum acceleration and velocity ranges are specified. These ranges can be dynamically generate on the planned path by the manipulator. The path can be altered by considering the geometrical constraints. Later, considering the impulsive force constraint on the object, the range of maximum acceleration and velocity are obtained to preserve object safety while the manipulator is carrying it along the curved path. Finally, a time-optimal trajectory is planned within the maximum allowable range of acceleration and velocity. This time-optimal trajectory planning can be applied to real applications and is suitable for both continuous and discrete paths.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.40-46
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• 2003

Synchronizing errors between the spindle motor and the z-axis motor directly influences the cutting characteristics and the thread quality in tapping, because the tapping process is accomplished by synchronizing the movement of the z-axis with the revolutionary spindle motion. Generally synchronizing errors are decided by tile parameters of the servo system and commanded velocity. The excessive synchronizing errors which are induced by the parameter mismatch and high cutting velocity can cause tap breakage due to the abrupt increase of cutting torque or damage the thread accuracy by overcutting the already cut threads. In this paper, the influences of the synchronizing errors on the tapping characteristics in the ultra high-speed tapping will be described and a minimum level of synchronizing errors necessary to maintain the quality of the cut thread will be presented.

• Food Science and Biotechnology
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• v.14 no.2
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• pp.286-289
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• 2005

Active antibacterial compound against periodontitis-causing bacterium Porphyromonas gingivalis was isolated from Kaempferia pandurata and identified as panduratin A. Minimum inhibitory concentration (MIC) value of panduratin A was $4\;{\mu}g/mL$, much lower than those of other natural antibacterial agents. Panduratin A also showed antibacterial activity against Prevotella intermedia ($2\;{\mu}g/mL$), P. loescheii ($4\;{\mu}g/mL$), and cariogenic Streptococcus mutans ($4\;{\mu}g/mL$). Damage on cell wall and perturbation of cytoplasmic membrane of panduratin A-treated P. gingivalis were visualized through transmission electron microscopy. These results suggest panduratin A, exhibiting strong and preferential antiperiodontal and anticariogenic activities, may be utilized in functional foods for prevention of oral diseases.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.330-337
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• 2002

The objective of the earthquake resistant design of structures is to satisfy on the one side the minimization of damage requirement under earthquakes with high probability of occurrence during the design life and on the other side the no collapse requirement under the design seismic event with low probability of occurrence. The two requirements are satisfied with the minimum strength of substructure as well as the ductile failure mechanism presented in the codes. In this study seismic performance is evaluated with two bridges which have steel box superstructures and T type, II type piers as substructures. In order to satisfy the two requirements redesign of both substructures and steel bearings are carried out.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.132-137
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• 2001

Miniaturized specimen technology is useful to characterize the mechanical behavior using a minimum volume of material, because it is almost impossible to sample the conventional specimen for the fracture toughness test without damage to equipment. Test material was 1Cr-1Mo-0.25V steel which was widely used for turbine rotor material. Two kinds of miniaturized impact specimens were prepared, i.e., miniaturized specimen with side groove and without side groove. The correlation between ductile brittle transition temperature(DBTT) of full size impact specimen and that of miniaturized impact specimen was made. The characteristics of miniaturized impact specimens technique as well as fracture stress were discussed. Finally, we concluded that the characteristics of fracture stress change on aging time were similar to that of DBTT.