• Journal of the Korean Chemical Society
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• v.10 no.3
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• pp.109-113
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• 1966

By the micro-bioassay method, quantitative studies were made on the increment of body weight and changes in free-lysine and threonine contents in the liver and plasm of rats, when they were fed on sucrose diet added with 0.3% DL-methionine, 0.36% DL-threonine and 0.1% L-tryptophane. The results of the experiment were as follows: (1) The weight gain and growth gain of rats decreased more when they were fed on 0.36% DL-threonine diet (Sth-group) than 0.3% DL-methionine diet (Sm-group). But those gain were increased when they were fed on 0.1% L-tryptophane diet (Str-group). (2) The contents of free-lysine and threonine in plasm and liver of rats were decreased more when they were fed on 0. 36% DL-threonine diet than 0.3% DL-methionine diet. And, those free amino acids were increased greatly when they were fed on 0.1% L-tryptophane diet. (3) The increment of body weight was the biggest when the free amino acid pattern showed that the contents of free-lysine decreased and threonine increased in the plasm and liver of rats being fed on 0.l% L-tryptophane diet.

• Convergence Security Journal
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• v.2 no.1
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• pp.99-107
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• 2002

This paper proposes a group key management protocol for a secure of all the multicast user in PIM-SM multicast group communication under electronic commerce. Each subgroup manager gives a secure key to it's own transmitter and the transmitter compress the data with it's own secure key from the subgroup manager. Before the transmitter send the data to receiver, the transmitter prepares to encrypt a user's service by sending a encryption key to the receiver though the secure channel, after checking the user's validity through the secure channel. As the transmitter sending a data after then, the architecture is designed that the receiver will decode the received data with the transmitter's group key. Therefore, transmission time is shortened because there is no need to data translation by the group key on data sending and the data transmition is possible without new key distribution at path change to shortest path of the router characteristic.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.22-24
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• 1996

Small size DC motor control method for portable drug delivery system has been developed to be used for the actuator of insulins pump. The control method gives the controllabilities both in high speed(40-50 revolution per second(rps)) DC motor drive and also in low speed(0.5-1rps). In low speed mode DC motor is controlled to act like stepping motor and in high speed to optimize power consumption. To control both mode modified bang bang control is suggested. Using this method small size DC motor(spec.) speed is controlled from 0.2 rps to 50 rps. Experimental setup is developed using micro-processor(PIC16C73, Micro Chips co., USA), motor turns checking circuitry, small size DC motor for pager(SM1012, Samhong co., Korea) and gear box. Results from experiment meet need for vailable load condition which is require for portable drug delivery system.

• Nuclear Engineering and Technology
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• v.50 no.6
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• pp.869-876
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• 2018

The force of a direct current (DC) electromagnetic pump used to transport liquid lithium was analyzed to optimize its geometrical and electrical parameters by numerical simulation. In a heavy-ion accelerator, which is being developed in Korea, a liquid lithium film is utilized for its high charge-stripping efficiency for heavy ions of uranium. A DC electromagnetic pump with a flow rate of $6cm^3/s$ and a developed pressure of 1.5 MPa at a temperature of $200^{\circ}C$ was required to circulate the liquid lithium to form liquid lithium films. The current and magnetic flux densities in the flow gap, where a $Sm_2Co_{17}$ permanent magnet was used to generate a magnetic field, were analyzed for the electromagnetic force distribution generated in the pump. The pressure developed by the Lorentz force on the electromagnetic force was calculated by considering the electromotive force and hydraulic pressure drop in the narrow flow channel. The opposite force at the end part due to the magnetic flux density in the opposite direction depended on the pump geometrical parameters such as the pump duct length and width that defines the rectangular channels in the nonhomogeneous distributions of the current and magnetic fields.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.654-658
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• 2012

국내에서 수행한 대부분의 제방 침투에 대한 수리모형실험 연구는 제체만을 대상으로 수행되었으며, 투수성 기초지반을 고려한 연구는 찾아보기 어려운 상황이다. 이 연구에서는 개정된 제방설계기준에 따른 1:3의 비탈경사와 투수성 기초지반을 가지는 제방의 침투실험을 수행하였으며, 향후 제방침투 수치모의에 필요한 검보정 자료를 확보할 목적으로 수행하였다. 부산광역시 강서구에 위치한 낙동강 제2하구둑 건설 현장에서 제체의 재료를 채취여 입도분석과 들밀도시험을 통해 제방의 건조단위중량과 다짐도 및 제방의 투수계수는 각각 $1.372g/cm^3$, 93%, 1.35 m/day이며 통일분류법의 SM에 속하는 것으로 확인하였다. 0.45 m, 0.50 m, 0.55 m, 0.60 m의 4가지 수위(각각 Case-1~4) 조건에 대하여 정상상태에 도달할 때까지 실험을 계속한 결과 각각의 실험조건별 침윤선은 대체로 동일한 양상을 보였지만 몇 지점에서 위압수두계 수위의 이상점이 발견되었다. 제방을 해체하면서 원인을 찾아본 결과 머드볼이 형성되어 있음을 확인하였으며, 침투 흐름에 상당한 영향을 미쳤을 것으로 생각된다.

• Journal of Welding and Joining
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• v.7 no.4
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• pp.56-67
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• 1989

In this study, the possibility of evaluating the peculiar fracture strength of weldment in high strength steels was investigated by means of a small punch(SP) test. In order to obtain the ductile-brittle transition temperature(DBTT) of SP energy by which the fracture strength of weldment in structural steels such as SS41 and SM53B steels had been evaluated in our preceding publication, the effects of notches and loading rates on SP energy were discussed. It was found that the correspondence of SP energy to critical COD at test temperature -196.deg. C showed a linear relation with some deviation. The empirical correlation with scatter band, Esp/(Esp)p = 1.67[.delta./(.delta./sub c//(.delta./sub c/)/sub p/]-0.55, was developed between the SP energy ratio and critical COD ratio of each weld structure compared with parent material at test temperature -196.deg. C. In addition, there did not appear to be a significant effect of test materials and specimen size etc. on the correlation.

• Journal of Welding and Joining
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• v.5 no.3
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• pp.53-61
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• 1987

Post weld heat treatment(PWHT) is usually carried out to remove the residual stress and to improve the microstructure and mechanical properties of welded joints. By the way, welding structure transformed owing to PWHT and reheating for repair loads the random cycles fatigue as offshore welding structure of constant low cycle fatigue as pressure vessel, and then, pre-existing flaws or cracks exist in a structural component and those cracks grow under cyclic loading. Therefore, the effects of PWHT and stress ratio on fatigue crack growth behaviors were studied on the three regions such as HAZ, sub-critical HAZ and deposit metal of welded joints in SM53 steel. Fatigue crack growth behavior of as-weld depended on microstructure and fatigue crack growth rate of HAZ was the lowest at eac region, but after PWHT it was somewhat higher than that of as-wel. In case of applying the stress($10kg/mm^2$) during PWHT, fatigue crack growth resistance tended to increase in the overall range of .DELTA.K.

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.3
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• pp.136-141
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• 2020

The purpose of this study was to investigate the action mechanism of the roots of Adenophora triphylla var. japonica extract (ATE) in 3T3-L1 adipocytes. Cell toxicity test by MTT assay and lipid accumulation was performed to evaluate the inhibitory effect on the differentiation of adipocyte from preadipocytes induced by MDI differentiation medium, while adipogenesis related proteins expression level were evaluated by western blotting. As a result, ATE inhibited MDI-induced adipocyte differentiation in 3T3-L1 cells dose-dependently without cytotoxicity. Our results showed that ATE inhibited the phosphorylation of IRS1, thereby decreasing the expression of PI3K110α and reducing the phosphorylation of AKT and mTOR, resulting in attenuated protein expression of C/EBPα, PPARγ, ap2 and FAS in 3T3-L1 cells. These results suggest anti-adipogenic functions for ATE, and identified IRS1 as a novel target for ATE in adipogenesis.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.2
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• pp.127-131
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• 2006

Radiosynovectomy has been used as an effective treatment in patients with resistant synovitis after failure of long-term medication and intraarticular steroid injection. Although $^{90}Y$ silicate/citrate, $^{186}Re$ sulfide, and $^{169}Er$ citrate were approved in Europe for the appropriate radiopharmaceuticals for radiosynovectomy other radionuclides such as $^{32}P$-chromic phosphate, $^{165}Dy$-ferric hydroxide macroaggregate, $^{188}Rh$-microspheres, $^{153}Sm-particulate, and $^{166}Ho$-ferric hydroxide macroaggregate have been used in many countries. Reported success rates range from 40% to 90% for the different joints and underlying disease. In Korea, $^{188}Re$-tin-colloid and $^{166}Ho$-chitosan complex are now using as the major radionuclides in radiosynovectomy with good clinical results. A study on radiation synovectomy using $^{188}Re$-tin-colloid for patients with Korean rheumatoid arthritis shows the treatment resulted in the improvement of arthritis and well tolerated in our study, the radiosynovectomy with $^{166}Ho$-chitosan complex in 53 hemophilic patients markedly decreased intra-articular bleeding frequency and need for coagulation factor. This review inculdes general priciples in the application of radiosynovectomy and the clinical experience in Korea.

• Journal of the Korean Society for Heat Treatment
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• v.3 no.2
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• pp.32-36
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• 1990

For the accurate measurements of hardness in a material, it is necessary to have a thorough understanding of the effects of test variables on the accuracy of hardness value. For the rebound hardness test, major test variables are the radius of hammer ball tip, type of backing materials, size and roughness of the specimen. In this study, effects of these variables on Equo-Tip hardness value were investigated. Hardness measurements were carried out using WC balls with various sizes of worn-ot zone. The sample materials chosen for the experiments were commercial standard hardness blocks and SM45C steel bars subjected to either normalization or quench and temper treatments. As backing materials, aluminum, steel and rubber plates were used in all the experiments. Experimental results show that for the accurate measurements of Equo-tip hardness, it is necessary to use the hammer ball with a worn-out zone parameter of less than 0.23, and the recommended minimum thickness and width of the specimen are 25mm and 70mm, respectively. Further for the surface preparation, the specimens need to be polished with an emery paper of No. 400 or finer, and for the backing matrials, it is recommended to use steels or rubbers.