• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.2
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• pp.123-129
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• 2017

Objectives: The purpose of this study is to enhance the application of analytical method of polar solvents(alcohols) by GCOTC (gas chromatography open tubular column) through the system suitability test(SST) to estimate the whole chromatographic system performance(integral part). Methods: To perform the SST, carried out repeatability(n=6) as analytical method of polar solvents by GCOTC, got the retention time($t_R$), standard deviation(${\sigma}_{n-1}$) of $t_R$, baseline width($w_b=4{\sigma}_{n-1}$) and calculated dead time($t_m$) by $v_m=d^2{\pi}L(f/4)$ and $v_m=t_m$ x flow rate. Results: In this experiment, obtained the basic data, there were $t_m=2$ min, methanol($t_R=3.569$, ${\sigma}_{n-1}=0.01$, $w_b=0.04$), ethanol ($t_R=3.892$, ${\sigma}_{n-1}=0.004$, $w_b=0.016$), isopropanol($t_R=4.209$, ${\sigma}_{n-1}=0.004$, $w_b=0.016$). By using these data, calculated the corrected retention time($t_R{^{\prime}}$), capacity factor(k), separation factor(${\alpha}$), number of theoretical plate(n) and resolution($R_s$) for SST and got the good results. Conclusions: Through the SST, could reconfirm the whole chromatographic performance system(integral part) for analytical method of polar solvents by GCOTC. Therefore, this analytical method expect to be widely applied at the related areas.

• Journal of the Chungcheong Mathematical Society
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• v.28 no.4
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• pp.499-511
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• 2015

This paper shows that the solutions to the perturbed dierential system $$y^{\prime}=f(t,y)+{\int}_{t_o}^{t}g(s,y(s))ds+h(t,y(t),Ty(t))$$ have bounded property. To show this property, we impose conditions on the perturbed part ${\int}^{t}_{t_o}g(s,y(s))ds+h(t,y(t),Ty(t))$ and on the fundamental matrix of the unperturbed system y' = f(t, y).

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.121-124
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• 2004

The purpose of this study is to define the optimized layer pattern of composite wind turbine blade by using a commercial FEM program and to perform the fatigue test of T-Bolt. FEM analysis is done by using a PATRAN and ABAQUS to get a information about stress distribution ,critical deformation shape and get a critical load factor in local buckling analysis. As a result of the linear and nonlinear structural analysis, layer pattern of blade was optimized. T-Bolt is a connecting part of wind turbine blade and rotor hub, therefore T-bolt is cirtical part of wind turbine blade. T-bolt fatigue test is conducted to get a information of life cycle of T-bolt. The test is done by using a hydraulic actuator system

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.528-533
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• 2005

This paper presents the study of flows at T-junction pipe with orifices. Experiments were carried out for several flow rates, orifice sizes, and pressure differences. Numerical simulations were also done to get more data for the wide range of flow rates. Experimental results and numerical ones are in a good agreement. Due to the effect of T-junction part, the flow rates at the lateral pipe are greater than those at straight pipe for the same pressure differences. When orifices were added, the effects of T-junction part on the ratio of flow rates and the ratio of loss coefficients reduced.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.4
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• pp.68-72
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• 2004

In this paper, the energy conversion theory of the linear actuator deals with the temperature characteristic analysis with verifying temperature of linear Actuator system This model of linear actuator has winding part and mechanical spring, and a plunger. This paper proposed and experimented the linear Actuator(LA) by using finite difference equation(FDE). The experimental result represented the temperature T1 and T2 which remarks Tl is a center of magnetic road inside of actuator winding part, and T2 is a surface of actuator winding part. And the temperature characteristic of the actuator winding part are experimented by the digital temperature meter TECPEL 322.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.340-343
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• 2005

This paper focuses on an rheo-forming of arm part fabricated by electromagnetic stirring system (EMS). This forming process take place under high pressure of high pressure die casting and thin walled casting is possible. Also the productivity is better than low pressure die casting because of shorter cycle time. The advantages of rheo-forming are performed in the semi solid state with laminar flow and the gas content is low, which makes welding possible. Therefore this research applies for arm part with EMS and has investigated the mechanical propriety after T6 and T5 heat-treatment.

• Electronics and Telecommunications Trends
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• v.9 no.1
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• pp.25-36
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• 1994

통신 시스템의 확실한 연속 서비스 목표를 만족시키기 위한 최적의 spare part 수준을 결정하는 데에는 고장률과 spare part의 인도기간이 크게 기여한다. 따라서 본고는 관련 비용인자와 함께 통신시스템의 최적 spare part 수준결정모델의 결정에 관해 중점을 두고 서술하였다. 이 모델은 통신시스템을 구성하는 plug-in PBA의 spare 수준을 결정하는데 유용하게 적용될 것이며 또한 연도별 시설 공급계획에 의거 운용보전국(OMC) 단위로 적용할 때 특히 유용할 것이다.

• Journal of applied mathematics & informatics
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• v.40 no.5_6
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• pp.1167-1179
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• 2022

In this paper, we obtain some subsets of real numbers (ℝ) on which a fractional part function is defined as a real-valued continuous function. This gives rise to the analysis of the continuous properties of the fractional part function as a real-valued function. The analysis of fractional part function is helpful in the study of the dynamics of circle.

• Korean journal of food and cookery science
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• v.31 no.4
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• pp.423-430
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• 2015

This study was carried out to investigate the effects of dandelion leaf, root and whole part extracts on the physicochemical characteristics of pork patties stored at $4^{\circ}C$ for 10 days. Four types of pork patties were evaluated: ice-water-added (T0), dandelion leaf extract (T1), dandelion root extract (T2) and dandelion whole part extract (T3). The pH decreased significantly during storage, but increased after 10 days of storage. The pH was highest in T0 during storage. The L value of T0 increased whereas T1, T2 and T3 did not significantly changed during storage. The a value decreased with a longer storage period, and the a values for T1, T2 and T3 were higher than that of T0 during storage. The b value did not change significantly during storage. The TBARS increased with a longer storage period, and the values for T0, T1, T2 and T3 were 0.87, 0.29, 0.47 and 0.31 mg MA/kg, respectively, after 10 days of storage. The VBN content value of T0 increased, but those of T1, T2 and T3 did not significantly change during storage. The water holding capacity of T0 decreased, but those of T1, T2 and T3 did not significantly change during storage. Cooking loss increased during storage and that of T0 was higher than those of T1, T2 and T3. Hardness and chewiness decreased while springiness and cohesiveness increased during storage.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.5-9
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• 2003

The fused thoracic vertebra and deformity of the lumbar vertebrae in the female Thoroughbred horse were observed macroscopically. The 11th and 12th thoracic vertebrae (T) were partially fused. They were composed of three parts between the spinous process of the 11th and 12th T, left and right caudal articular processes of the 11th T, and left and right cranial articular processes of the 12th T. The vertical surface of cranial articular process of the 11th T and left mamillary process of the 12th T were absent. The left caudal part of the transverse process of the 12th T and left costal fovea of the transverse process of the 12th T were severely deformed. On the other hand, the left transverse process of the first lumbar vertebra (L) was a typical rib-like transverse process and two times longer than the right transverse process of the 2nd L. The right transverse process of 4th L has an oval concave facet on the medial part of caudal border for articulation with the right transverse process of 5th L; the latter has a corresponding convex facet on the medial part of the cranial border in the right transverse process of the 5th L.