• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1999.11a
• /
• pp.146-153
• /
• 1999

A numerical dynamic simulation is necessary to investigate the capacity of the HDD. The slider surface become more and more complicated to make the magnetized area smaller and readback signal stronger. So a numerical dynamic simulation must be preceded to develop a new slider in HDD. The dynamic simulations of air-lubricated slider bearing have been peformed using FIFD(Factored Implicit Finite Difference) method. The governing equation, Reynolds equation Is modified with Fukui and Kaneko model(FK model) which includes the first and the second-order slip. The equations of motion for the slider bearing are solved simultaneously with the modified Reynolds equation for the case of three degrees of freedom. The slider transient response for disk step bump and slider impulse force is given for various case and for iteration algorithm and new algorithm.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 2006.05a
• /
• pp.264-268
• /
• 2006

혈당강하 요구르트의 개발을 위해 Streptococcus salivarius subsp. thermophilus와 Lacto-bacillus acidophilus 145, Bifidobacterium infantis 혼합균주에 사균인 FK-23 유산구균, 피니톨, 식이섬유, 백강낭콩 추출 분말, 에리스리톨, 바나바 추출물 등의 기능성 성분을 포함한 요구르트를 제조하여 정상인과 혈당치가 높은 당뇨 환자를 대상으로 간이 임상시험을 실시하였다. 1. 정상인의 식후 혈당치는 일반 요구르트를 섭취했을 때보다 혈당 강하 요구르트 음용시 더 낮게 측정되었으며 임상대상자 대부분에서 동일한 현상이 나타났다. 2. 혈당치가 높은 당뇨환자 10명을 대상으로 식후 혈당치 변화 및 음용기간 중 혈당치 변화를 확인한 결과 혈당 강하 요구르트를 음용하기 전보다 음용 후 혈당치가 식후 30 당증가 억제율도 임상대상자의 80%가 감소하는 효과를 나타냈다. 3. 30일간 혈당 강하 요구르트를 음용한 후 식후 혈당치의 변화를 확인한 결과 음용전보다 음용 후 120분 경과 때, 혈당치가 59 mg/dL 감소하였으며 음용기간이 증가할수록 지속적으로 감소하는 경향을 나타내었다.

• Molecules and Cells
• /
• v.22 no.1
• /
• pp.1-7
• /
• 2006

The NFAT family of transcription factors plays pivotal roles in the development and function of the immune system. Their activation process is tightly regulated by calcium-dependent phosphatase calcineurin and has been a target of the immunosuppressive drugs cyclosporin A and FK-506. Although the clinical use of these drugs has dramatically increased the success of organ transplantation, their therapeutic use is limited by severe side effects. Recent studies for the calcineurin/NFAT signaling pathway have identified a number of cellular proteins that inhibit calcineurin function. Specific peptide sequences that interfere with the interaction between calcineurin and NFAT have also been characterized. Moreover, diverse approaches to identify small organic molecules that modulate NFAT function have been performed. This review focuses on the recent advances in our understanding of the inhibitory modulation of NFAT function, which may open up the additional avenues for immunosuppressive therapy.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.1
• /
• pp.109-112
• /
• 2011

A new derivative of tacrolimus was evaluated for its molecular weight, using LC-MS of the tacrolimus bulk active pharmaceutical ingredient (API) recovered through the purification of crude tacrolimus produced by Streptomyces clavuligerus CKD-1119. In addition, the molecular weight of the new derivative of tacrolimus was found to be at m/z 818 and was identified by $^{13}C$-NMR with peak assignments based on the differences in methyl group location resulting from the chemical structure. The structure of the new derivative, an unknown impurity of tacrolimus, was found to be 18-methyltacrolimus through comparison of the spectral data of the structural differences between ascomycin, tacrolimus, and the new derivative 18-methyltacrolimus.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2009.04a
• /
• pp.165-171
• /
• 2009

A compound agent that mixes inert gas agents and halocarbon agents and a complex fire suppression system using the compound agent have been developed. The ultimate goal of this study is to develop the extinguishing agent which doesn't destroy the ozone layer and has low GWP and to develop the fire suppression system. As a result of the test and research for inert gas agents and halocarbon agents, nitrogen and FK-5-1-12 were selected finally and have been tested and studies for three years. Thus, the optimal extinguishing agent and fire suppression system have been accomplished. The performance of the agent and system was tested according to KFI performance test technical standards for gas fire extinguishing system and the fitness of the agent and system for a fire was certified by Korea Fire Industry Technology Institute (KFI).

• Journal of Microbiology and Biotechnology
• /
• v.29 no.6
• /
• pp.897-904
• /
• 2019

Monascus purpureus recombinant mppC and mpp7 knockout strains were subjected to extractive fermentation in the context of azaphilone pigment production. Inclusion of Diaion HP-20 resin resulted in the selective production of unreduced azaphilone congeners, in addition to the early intermediate FK17-P2a, from ${\Delta}mppC$ and ${\Delta}mpp7$ strains that would otherwise mainly produce reduced congeners. Structural determination of two novel unreduced azaphilones from the ${\Delta}mpp7$ strain was accomplished. The unreduced azaphilone compound was converted into the cognate reduced congener in recombinant M. purpureus strains, demonstrating its intermediate role in azaphilone biosynthesis. This study demonstrates the possibility that extractive fermentation with Diaion HP-20 resin can be used to obtain cryptic azaphilone metabolites.

• Proceedings of the PSK Conference
• /
• 2002.10a
• /
• pp.306.2-306.2
• /
• 2002

The main targets for the immunosuppressive calcineurin inhibitors. tacrolimus (FK-506) and cyclosporine A (CsA). have been considered to be activated T cells. but not antigen presenting cells (APCs). In the present study. we examined the effects of these drugs on the MHC-restricted presentation of exogenously added antigen. ovalbumin (OVA). in dendritic cells (DCs). Particulate form of OVA was efficiently captured. processed and presented on class I MHC molecules (cross-presentation) as well as on class II MHC molecules. (omitted)

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.12 no.1
• /
• pp.297-313
• /
• 2020

An Arctic Spar is characterized by its conical shape near the waterline. In this case, the nonlinear effects from its irregular hull shape would be significant if there is either a large amplitude floater motion or steep wave conditions. Therefore, in this paper, the nonlinear effects of an Arctic Spar are numerically investigated by introducing a weakly nonlinear time-domain model that considers the time dependent hydrostatic restoring stiffness and Froude-Krylov forces. Through numerical simulations under multiple regular and irregular wave conditions, the nonlinear behavior of the Arctic Spar is clearly observed, but it is not shown in the linear analysis. In particular, it is found that the nonlinear Froude-Krylov force plays an important role when the wave frequency is close to the heave natural frequency. In addition, the nonlinear hydrostatic restoring stiffness causes the structure's unstable motion at a half of heave natural period.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.5 no.2
• /
• pp.61-69
• /
• 2003

Surface energy and $CO_2$ fluxes have been measured over a farmland in Haenam, Korea since July 2002. Eddy covariance technique, which is the only direct flux measurement method, was employed to quantitatively understand the interaction between the farmland ecosystem and the atmospheric boundary layer. Maintenance of eddy covariance system was the main concern during the early stage of measurement to minimize gaps and uncertainties in the dataset. Half-hourly averaged $CO_2$ concentration showed distinct diurnal and seasonal variations, which were closely related to changes in net ecosystem exchange (NEE) of $CO_2$. Daytime maximum $CO_2$ uptake was about -1.0 mg $CO_2$ m$^{-2}$ s$^{-1}$ in August whereas nighttime $CO_2$ release was up to 0.3 mg $CO_2$ m$^{-2}$ s$^{-1}$ during the summer. Both daytime $CO_2$ uptake and nighttime release decreased gradually with season. During the winter season, NEE was from near zero to 0.05 mg $CO_2$ m$^{-2}$ s$^{-1}$ . FK site was a moderate sink of atmospheric $CO_2$ until September with daily NEE of 22 g $CO_2$ m$^{-2}$ d$^{-1}$ . In October, it became a weak source of $CO_2$ with an emission rate of 2 g $CO_2$ m$^{-2}$ d$^{-1}$ . Long-term flux measurements will continue at FK site to further investigate inter-annual variability in NEE. to better understand these exchange mechanism and in-depth analysis, process-level field experiments and intensive short-term intercomparisons are also expected to be followed.

• Korean Journal of Environment and Ecology
• /
• v.28 no.6
• /
• pp.650-656
• /
• 2014

This study was executed in Woraksan National Park from Febuary, 2008 to December, 2013 in order to study the behavioral characteristics of introduced four female gorals using annual home range, seasonal home range, and elevation use characteristics. Annual home range of reintroduced female gorals were $1.13{\pm}0.32km^2$ of MCP 95%, $0.37{\pm}0.18km^2$ of MCP 95% and $0.07{\pm}0.03km^2$(t=0.607, p>0.05) of FK 50% respectively. In seasonal home range and elevation use characteristics of MCP 95%, autumn($0.73{\pm}0.26km^2$) and summer($0.77{\pm}0.06km^2$) were the largest home range and spring($0.58{\pm}0.38km^2$) and winter($0.47{\pm}0.25km^2$) had a smaller home range and it showed that there was a difference between summer and winter home ranges(F=3.868, P<0.05). As a result of seasonal elevation analysis, elevation use was 435m(28.4%) in spring, 464m(26.7%) in summer, 414m(28.8%) in autumn, and 393m(21.2%) in winter, respectively. It showed that these gorals used higher elevation in summer(F=0.783, P>0.05). We could not analyze the characteristics of introduced gorals, because only introduced female gorals were used for this study. However, we could understand that habitat use characteristics were of statistical significance in introduced gorals from the analyses of their home range, seasonal home range and elevation use.