• Communications of the Korean Mathematical Society
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• 제26권3호
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• pp.499-513
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• 2011

By using the Riccati transformation technique, we study the oscillation and asymptotic behavior for the third-order nonlinear delay dynamic equations $(c(t)(p(t)x^{\Delta}(t))^{\Delta})^{\Delta}+q(t)f(x({\tau}(t)))=0$ on a time scale T, where c(t), p(t) and q(t) are real-valued positive rd-continuous functions defined on $\mathbb{T}$. We establish some new sufficient conditions which ensure that every solution oscillates or converges to zero. Our oscillation results are essentially new. Some examples are considered to illustrate the main results.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 한국측량학회 2003년도 춘계학술발표회 논문집
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• pp.229-236
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• 2003

In this study, for efficient replacemen of sensor modelling of high-resolution satellite imagery, image segmentation method is applied to the test area of the SPOT-3 satellite imagery. After that, a third-order polynomial model in the sectioned area is compared with the RFM which is to the entire in the test area. As results, plane error of the third-order polynomial model is lower(approximately 0.8m) than that of RFM. On the other hand, height error of RFM is lower(approximately 1.0m).

• International Journal of Air-Conditioning and Refrigeration
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• 제6권
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• pp.80-92
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• 1998

A third-order simulation model of a Vuilleumier{VM) heat pump has been developed. This model takes into account the major losses such as the heat conduction losses through regenerators and displacers, the pumping losses and the wall-to-gas heat transfer losses in active volumes, in addition to the heat exchanger and regenerator losses. The working volume was divided into 12 control volumes and the conservation equations of mass and energy were applied to each control volume. Pressure drops were considered in regenerators only. Thermodynamic behavior of the working gas in a VM heat pump was investigated and effects of the major losses and operating conditions on the performance of a VM heat pump were shown.

• Journal of the Optical Society of Korea
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• 제19권6호
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• pp.679-686
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• 2015

This paper presents a design method for improving the low relative illumination and large distortion due to widening the field of a system. A tele-centric optical system in image space was suggested to increase the relative illumination. Through the analyses of the third-order aberrations affected by introducing aspherical surfaces, we have proposed a method to determine analytically what surface should be aspheric to correct each aberration effectively. By utilizing this method to design a wide field lens, a tele-centric wide field lens with f-number of F/2.0 was obtained. Even though the field angle is 120 degrees, it has a very low distortion less than -2% and high relative illumination more than 73.7%. In conclusion, this analytic method for selecting aspherical surfaces is expected to serve as a useful way to find design solutions.

• Journal of the Chungcheong Mathematical Society
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• 제23권3호
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• pp.443-452
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• 2010

This work deals with the existence of uncountably many bounded positive solutions for the third order nonlinear neutral delay differential equation $$\frac{d^3}{dt^3}[x(t)+p(t)x(t-{\tau})]+f(t,x(t-{{\tau}_1}),{\ldots},x(t-{{\tau}_k}))=0,\;t{\geq}t_0$$ where ${\tau}>0$, ${\tau}_i{\in}{\mathbb{R}^+}$ for $i{\in}\{1,2,{\ldots},k\}$, $p{\in}C([t_0,+{\infty}),{\mathbb{R}^+})$ and $f{\in}C([t_0,+{\infty}){\times}{\mathbb{R}^k},{\mathbb{R}})$.

• The korean journal of orthodontics
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• 제11권2호
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• pp.77-83
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• 1981

The author analyzed the morphological pattern of mandibles and lower third molars in order to study and predict the impaction of the developmental third molars. The subjects consisted of 37 males and 87 females with malocclusion. The following results were obtained: 1. The mandible was shown to be shorter in the impacted third molar group than in the erupted group, both in over-all length and in body length. 2. The developmental mesial angulation of the third molar to the mandibular plane was higher in the impacted third molar group. 3. There was a tendency for impacted third molars to be slightly larger than those which erupted except Class II malocclusion in female. 4. In the available space for the eruption of the third molar, significant space deficiency was found in association with the impacted third molar group compared with the erupted group.

• Asian Journal for Public Opinion Research
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• 제11권4호
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• pp.274-303
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• 2023

The third-person perception phenomenon can consistently be found in opinion poll news, but it remains unknown what determines the degree of the third-person perception (TPP) about specific election poll news. We investigated how respondents' preferred candidate's status in the poll affects the perceived impact of polling news on both themselves (PMI1) and on others (PMI3) as well as TPP (PMI3 - PMI1). We also examined the effect of subjective political knowledge and the perceived level of political knowledge of others on TPP. An online experiment was conducted in the context of a gubernatorial election in South Korea, in which the leading candidate in the poll and the question order (self-question first vs. other-question first) were manipulated. The results indicated that PMI1 and PMI3 were greater when the respondent's preferred candidate was leading in the poll. TPP did not differ depending on subjective knowledge, but it was greater when the others were non-experts (vs. experts). Lastly, question order was found to be a method factor that affected both PMI1 and PMI3. The theoretical and practical implications of these findings are discussed.

• Journal of Acupuncture Research
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• 제18권5호
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• pp.33-42
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• 2001

Objective : To evaluate the effect of treatment for Rheumatoid arthritis by using Bee-venom Acupuncture that is well known for anti-inflammatory effect and function of activating immune system. Methods : Evaluated the result of Bee-venom Acupuncture treatment twice in a week for patients who diagnosised as rheumatoid arthritis by 7 criteria of US Rheumatism Academy. Results : 1. If you see the distribution chart, sexual rate of male and female was 1:2.75 and age distribution shows as age ascend it shows high. 2. If you see the duration distribution, it shows chronic tendency in order of more than 6 months (59.5%), 2 to 5 months, and 1 month. 3. If you see the invaded region distribution, it shows chronic tendency in order of finger(17 cases), wrist joint(16 cases), knee joint(16 cases), ankle joint(10 cases), elbow joint(8 cases), shoulder joint(7 cases), feet(7 cases), hip joint(5 cases), low back(3 cases) and neck(2 cases). 4. If you see the result of duration distribution treatment, the improvement index is rising in order of within a month, 2 to 5 months, and over 6 months. So it shows that it has good result of treatment within a month. 5. If you see the invaded region, it shows high improvement index in order of low back, hop joint, shoulder joint, wrist joint, feet, knee joint, finger, elbow joint, ankle joint and neck. 6. If you see the result of morning stiffness time before treatment, it shows good effect of treatment in order of 2-3hrs, 30min.-an hr, an hr to 2hrs, and 0-30min. 7. If you see the patients satisfaction after Bee-venom Acupuncture treatment, Excellent is 6 cases, Good is 7 cases, and Moderate 2 cases. Conclusions : It will have greater treatment effect if herbal medicine, moxibustion, and acupuncture are used together as patients whole body condition and symptoms with Bee-venom Acupuncture for rheumatoid arthritis that is chronic inflammatory disease.

• Smart Structures and Systems
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• 제5권5호
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• pp.531-546
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• 2009

In the present analysis, the spline finite strip with higher-order shear deformation is formulated for the static analysis of piezoelectric composite plates. The proposed method incorporates Reddy's third-order shear deformation theory, Touratier's "Sine" model, Afaq's exponential model, Cho's higher-order zigzag laminate theory, as well as the classic plate theory and the first-order plate theory. Thus, the analysis can be conducted based on any of the above-mentioned theories. The selection of a specific method is done by simply changing a few terms in a 2 by 2 square matrix and the results, obtained according to different plate theories, can be compared to each other. Numerical examples are presented for piezoelectric composite plates subjected to mechanical loading. The results based on different shear deformation theories are compared with the three-dimensional solutions. The behaviours of piezoelectric composite plates with different length-to-thickness ratios, fibre orientations, and boundary conditions are also investigated in these examples.

• Structural Engineering and Mechanics
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• 제27권1호
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• pp.1-16
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• 2007

In the present study, a spline finite strip with higher-order shear deformation is formulated for the stability and free vibration analysis of composite plates. The analysis is conducted based on Reddy's third-order shear deformation theory, Touratier's "Sine" model, Afaq's exponential model and Cho's higher-order zigzag laminate theory. Consequently, the shear correction coefficients are not required in the analysis, and an improved accuracy for thick laminates is achieved. The numerical results, based on different shear deformation theories, are presented in comparison with the three-dimensional elasticity solutions. The effects of length-to-thickness ratio, fibre orientation, and boundary conditions on the critical buckling loads and natural frequencies are investigated through numerical examples.