• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.487-493
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• 2004

This study has been undertaken to increase availability of native camellia in Jeonnam as a medicinal resource and to isolate the effective components from them. Fresh leaf and flower of camellia, single camellia tea and camellia tea mixed with green tea, herbs were screened for cytotoxicity on MCF -7 (human breast adenocarcinoma pleual effusion), Calu-6 (human pulmonary carcinoma), SNU-601 (human gastric carcinoma) cells. Also their multidrug-resistance reversing activity were evaluated using drug sensitive AML-2/WT and multidrug-resistant AML-2/D100 cells. Among the camellia extracts, young leaf and camellia tea mixed with green tea had strong growth inhibitory effects in below 100 $\mu\textrm{g}$/mL against human cancer cells. In result, young leaf showed the strongest inhibitory effects on MCF -7 ($IC_{50}$/ = 100 $\mu\textrm{g}$/mL ↑), Calu-6 ($IC_{50}$/ = 79 $\mu\textrm{g}$/mL), and SNU -601 ($IC_{50}$/ = 39 $\mu\textrm{g}$/mL), and AML-2/WT ($IC_{50}$/ = 64 $\mu\textrm{g}$/mL). Chemosensitizing effect was the extracts of mature leaf ($IC_{50}$/ = 97 $\mu\textrm{g}$/mL, RF=3.0), roasted tea ($IC_{50}$/ = 76 $\mu\textrm{g}$/mL, RF = 2.6 ↑) and steam tea ($IC_{50}$/ = 70 $\mu\textrm{g}$/mL, RF=2.8 ↑) strongly potentiate vincristine cytotoxicity in AML-2/D100 cells. But their cytotoxicities to both sensitive AML-2/WT and resistant AML-2/D100 cells were in the same order of magnitude. This results indicate that crude extracts of camellia mature leaves would contain some principles which have chemosensitizing activity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.53-59
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• 2019

To reduce the vibrations and shocks during the cargo transportation of high value-added goods, the vibration history was measured on the truck transportation section (Asan-Uiwang) and the freight train transportation section (Uiwang-Pusan). The internal vibrations of the container were obtained by attaching acceleration sensors in three axis directions (longitudinal, lateral. and vertical directions) on the front and rear bogies. The rail vibration profile (0.29Grms) proposed in ASTM D-4169 was approximately 50% higher than the truck vibration profile (0.54Grms). The overall vibration was 16% and 33 % lower in the longitudinal and transverse directions, respectively, compared to the ASTM truck transport vibration profile. On the other hand, the vertical vibration measurement history partially exceeded the ASTM truck transport vibration profile over the range, 4 - 15Hz, and over 60Hz. The vibration measurement history of the cargo train was similar to that of the road. The longitudinal and lateral vibration history was lower than the ASTM D-4169 rail vibration profile, while the vertical history was over 30Hz.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.830-835
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• 2011

DMT Freight is judged that economic performance is good because can increase cargoes than existing freight. However, the existing freight cars, each with a different balance to the body structure is bogie because the vibrations may occur. Thus, by minimizing vibration over the existing freight securing the safety of the driving if you will not have major problems in cargoes. In this study, multi-body dynamic analysis tool, VI-Rail using the actually Gyeongbu Railroad line and an empty, full freight condition include curve radius, track irregularity, cent. DMT freight of the derailed wagons were assessed for safety analysis. Full and empty freight conditions for parity in the Gyeongbu Railroad line(Dongdaegoo ${\leftrightarrow}$Gyungsan) derailment safety analysis, such as derailment safety coefficient and the radius wheel road decrement, echoing the curve and the orbit is affected by the irregularity was found. Full freight condition than the empty conditions showed a significant derailment safety. Overall, the limits of derailment coefficient (Q/P=0.8) and wheel road decrement limits (${\Delta}P/P=0.6$) is less safe with me confirmed that the derailment safety.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.361-364
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• 2005

Some bogie frames manufactured in 1999, 2000 year have the fatal problem. Three or four years later, the cracked end beam among them have discovered in 2002, 2003 year. The crack situation of the end beam have a bad effect on brake system. In that case, the cars would be in danger of derailment. To improve the end beam, a research of covering the whole field of welded type bogie frame was started. Main line real tests were performed at Young-Dong line. The stress of main positions for bogie frame was measured. Also up-down direction and left-right direction vibration acceleration of the bogie frame were measured. At this time the tests were performed for the three types bogie. The test result concludes that the crack cause of the end beam is not brake load but vibration at running mainly. It is estimated that the life of the improved car which end beam reinforced is safe within the car permitted life(25 years). The improvement methods of the end beam are presented by construction modification, parts modification. The integrity evaluation is inspected by analysis the real line test results, the improvement methods of the end beam.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.4
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• pp.436-440
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• 2017

This study evaluated the design and structural integrity of a three-axle bogie frame in a railway freight car through a numerical analysis and an experimental evaluation. A three-axle bogie frame, which supports the weight of the car body and load, is required to transport heavier cargo because two-axle vehicles have structural limitations. Therefore, this study performed a structural analysis and static load tests to evaluate the design and structural integrity of a three-axle bogie frame. The results obtained from the numerical analysis were compared to those of the experiments. For the bogie frame used in the experiments, a failure evaluation was performed using non-destructive methods. The numerical analysis and experimental evaluation were satisfactory for the structural integrity evaluation.

• Proceedings of the KOR-KST Conference
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• 1995.05b
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• pp.202-230
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• 1995

0 동북아지역 경제의 급속한 성장과 남북경제교류 활성화로 수송 부문의 발달이 중요성을 더해 가고 있슴 0 그러나 지금까지 남북철도 연결에 관한 논의는 통일 후의 방안 만 고려되었을 뿐, 통일 전 남북철도 연결을 목표로 하는 구체 적 전략이 부재하였고, 특히 해운과의 경쟁력 비교시 철도시스 템에 대한 이해부족이 지적됨 0 남북 및 대륙연결 최적 철도망을 구축하기 위해서는 다음과 같 은 접근 방안이 효과적임 - 남북 철도연결은 순수 경제적 관점에서, 민간기업이 주체가 되어, 중국철도 등을 중개자로 하여 사업을 추진 - 단계적이며 실용적 접근전략에 따라, 1단계로는 경의선 만을 연결하고, 여객취급을 배제하며, 컨테이너 수송만으로 시작하다가, 광물자원 수송 등 확대 - 초기에는 남북간 수송보다는 한국과 중국 . 러시아 간의 컨테 이너 통과수송 취급에 중점 (북한의 수송수입 강조) - 경의선을 따라 남북 군사분계선 근처에 각측의 경계역을 만들 고, 상대촉 파견관의 검색 및 언수에 따라 열차가 휴전선을 통과하여, 반대펀 경계역에 이르면 기관차 및 승무원을 교체 하며, 화차는 일정 기간 이내 되돌려주는 방식 채택으로 남북 철도 시스댐 차이에 따른 기술적 문제 해소 0 대륙철도의 이용은 동북아 권역내 수송에 중점을 두되, E ESCAP의 활동에 따라 TCR,TSR을 이 용한 유럽 및 중동으로 의 수송도 추진하며, 남북 철도연결 추진과 병행하여 열차페리의 도입에 의한 철도- 해운 복합수송 방식의 활성화를 적극 검토활 것이 필요함

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11B
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• pp.1600-1606
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• 2001

Resonant frequency in rectangular microstrip patch antenna on anisotropic substrates with airgap and superstrate are analyzed. Dyadic Green function is derived for selected anisotropic material by constitutive relation. From these results, integral equations of electric fields are formulated using Fourier transform in space region. The electric field integral equations are discretized into the matrix form by applying Galerkin\`s moment method. Sinusoidal functions are selected as basis functions because they resemble in the actual standing wave on the patch. To verify the validity of numerical result, we compare our result with existing one and get a good agreement between them. From the numerical results, the resonant frequency in the variation of air gap, patch length and anisotropy ratio are presented and analysed.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.9
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• pp.186-192
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• 2002

As industry is developed, the faster transportation of freight train is demanded. The optimum design of a structure requires the determination of economical member size and shape of a structure which will satisfy the design conditions and the functions. In this study, it is attempted to minimize the dead weight of bogie frame. From the numerical results in the shape and size optimization of the bogie frame, it is known that the weight can be reduced up to 17.45% with the displacement, stress, first natural frequency and critical buckling-load constraints. The first natural frequency and the critical buckling load of the optimized model is larger than that of the lowest design value. Stress and displacement conditions are also satisfied within the design conditions. From the results, the optimal model is stable and useful for the improvement of railway carriages.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.10
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• pp.962-967
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• 2004

A bogie is the device that connects a car body and wheel sets of a rail vehicle. It is the critical component that determine:; the running safety, The bogie consists of a frame, suspensions, brakes and wheel sets. Various analyses including a numerical simulation using a finite element method, a static load test, a fatigue test, ai)d r running test should be carried out to design the bogie. However cracks have been found at some end beams of the bogies mounted on the freight cars running with the high speed. The cracks of the end beam results in deterioration of the brake performance an the running safety, A new design has been suggested to solve this problem by ROTEM company and it's performance has been tested in this paper. Numerical simulations and dynamic tests are carried out to figure out the causes of cracks in the conventional bogie, and the vibrational characteristics of the improved bogie are compared with those of the conventional one.

• Fire Science and Engineering
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• v.14 no.3
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• pp.19-26
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• 2000

As a basic physical property of chemical substances, the flash point is of great importance as far as the prevention of chemical disasters is concerned. The measurement of flash point is not easy. and the number of c(Impounds for which systematic data have been collected pitifully small. Because, a need exists for some means of predicting the flash point of compound for which experimental data are unavailable, not only those which are currently in use or at the production stage, but also, those not compounds which are in the process of synthesis and design. The present research concerns the application of OCD (organic conception diagram) to the association between chemical structures and flash points, and an attempt made to discover a method of predicting the approximate flash point of a compound from its chemical structure alone.