• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.3
• /
• pp.325-331
• /
• 2013

In this study, a complex eigenvalue analysis is implemented to verify the unstable mode of a brake system using ABAQUS software. The component participation factors and component modal participation factors are used to analyze the total contributions from each component and each component mode to a particular unstable system mode. This study shows that the 1.4-kHz unstable system mode comes from mode coupling between the 2nd nodal diametric mode and 3rd lateral axial mode (LAM) in the baseline model. A sensitivity analysis with a linking index is performed to prevent the mode coupling of the component modes. This linking index analysis shows the optimum mass loading position to move away the natural frequency of the 3rd LAM, which contributes to the unstable mode. Finally, a complex eigenvalue analysis is implemented with mass loading in the tie bar position, and no unstable system mode is generated in the low-frequency range (below 2 kHz).

• Journal of the Korean association of regional geographers
• /
• v.5 no.2
• /
• pp.29-45
• /
• 1999

This study reviewed theories on entrepreneurial local governance and inquired the changing regional policy in Chonnam region. The region became exposure as the direct investment unit of global capital by globalization of capital, the inter-regional competition and the relative reduction of the role and function of nation state. Therefore local government have the relative autonomy and the region is effected as the chosen space by capital according to the free movement of capital. It has been argued that there has been a reorientation of urban governance away from the local provision of welfare and services to a more outward-orientated stance designed to foster and encourage local growth and economic development. These profound changes in the way that cities operate have seen the public sector taking over characteristics once distinctive to the private sector leading many commentators to term such modes of governance as entrepreneurial. In Chonnam region, many local governments are introducing entrepreneurial policies for regional development. It appears as place marketing strategy to attract capital and tourists. This strategy is very important to used identity or culture of region in order to make the attractive region. The entrepreneurial characteristics and strategies appear as image unification of region, commodity development of natural or cultural resource, event and business projects. From this point of view, the entrepreneurial policy that is based upon regional growth can cause the problem of social justice like distributional distortion and inequality.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2018.04a
• /
• pp.14-14
• /
• 2018

This Camptotheca acuminata Decne. (CA), belonging to Nyssaceae, is a deciduous tree. and has been used as Traditional Chinese medicine since ancient times. The CA produces camptothecin a natural indole alkaloid, and reported to have anti-cancer effects. But the studies on biological activities of CA leaves are insufficient. Therefore, this study confirmed various biological activities such as antioxidant, antidiabetic, anticancer, antiinflammatory and metabolism analysis by HPLC-MS/MS of CA leaves. The $RC_{50}$ values of DPPH radical scavenging activity of ethyl acetate fraction, n-Butanol fraction, methanol extraction, water fraction and n-Hexane fraction were $12.23{\pm}0.01$, $15.93{\pm}0.42$, $55.12{\pm}0.45$, $56.29{\pm}4.15$ and $427.29{\pm}6.13ug/mL$, respectively. The $IC_{50}$ values of ${\alpha}$-glucosidase inhibitory activity of ethyl acetate fraction, n-Butanol fraction, methanol extraction, n-Hexane fraction and water fraction were $24.29{\pm}0.14$, $47.86{\pm}0.45$, $54.23{\pm}1.21$ $466.76{\pm}2.21$ and $623.91{\pm}9.67ug/mL$, respectively. The nitric oxide release activity of n-Hexane fraction, methanol extraction, ethyl acetate fraction, water fraction and n-Butanol fraction were $31.49{\pm}5.74$, $29.79{\pm}0.71$, $26.89{\pm}0.71$, $8.24{\pm}5.83$ and $7.75{\pm}4.08%$ at 25 ug/mL, respectively. The anti-cancer activity of n-Hexane fraction, methanol extraction, ethyl acetate fraction, water fraction and n-Butanol fraction were $31.49{\pm}5.74$, $29.79{\pm}0.71$, $26.89{\pm}0.71$, $8.24{\pm}5.83$ and $7.75{\pm}4.08%$ at 25 ug/mL, respectively. The ethyl acetate fraction activities showed higher biological activities than other fractions. Thus, Additional studies were conducted using ethyl acetate fraction. Metabolite analysis was performed using a LCMS-8040 triple quadrupole mass spectrometer. As a result, Five compounds (1-5) were identified in the ethyl acetate fraction of the CA leave. The identification of these compounds was generated by the analysis of fragmentation methods of the negative and positive ion modes. Five compounds were identified as gallic acid (1), chlorogenic acid (2), isoquercetin (3), astragalin (4) and camptothecin (5). These results suggest that the CA leave can be used for functional materials.

• The Research Journal of the Costume Culture
• /
• v.4 no.2
• /
• pp.247-263
• /
• 1996

This study focuses on a comparative study of 1960s'retro look mode in terms of the past and present in order to find out in detail how it in the past is readjusted after it was appeared in the present. For such a study, in the first place the contents of the dress and its ornament of a retro-look fashion was refined through some literature, and then, some works of the dress and its ornament of a retro-look fashion was refinded through some literature, and then, some works of eh dress and its ornament revived in 1960's mode were analysed, based on some fashion magazines at home and abroad like Bazaar, Fashion etc News in 1990s. After 1960s'retro-look mode which reappeared in 1990s was researched in terms of silhouette, detail, texture, color, and pattern, differences between those tow periods of 1960s and 1990s and their causes are summarized as follows: 1. In the aspect of silhouette, it appears that the silhouette in 1960s is that of somewhat stiff, charming image in which Body is excluded and the silhouette in 1990s is that of an soft, feminie image in which Body is emphasized. It was understood that the cause of such a delicate difference comes from the influences of the change in aesthetic senses or awareness, naturalism and neo-feminism. 2. In the aspect of detail, it appears that the detail in 1990s is of an attempt to express in diverse images, compared to that in 1960s, and new images are created new image in 1990s by means of presenting entirely ill-matched images. The major cause of that is because of Antistandard fashion. 3. In the aspect of textures, it appears that a great feature is that the texture in 1990s is of that introduced, being changed in natural and high-class looks, compared to that of 1960s. It was reviewed that the major cause of this is because of a result from the influence of naturalism and the technical growth in various fields which has brought the development of dress material. 4. In the aspect of color, it appears that the color in 1990s is of an image of primary color which is far more sensual and feminie than that of 1960s. It was studied that the major cause of ti comes from the influence of neo-feminism, etc. 5. In the aspect of pattern, it appears that the pattern in 1990s is of that of symbolism, transposition, and the ecletic feature of various modes which appear more deeply than that of 1960s. It was studied that the major cause of such changes is because of a trend of postmodernism which has brought the change of the spiritual structure different from that in the age of modernism. In conclusion, it was understood that the retro-look fashion is of an expression technic of dress and its ornament in that o dress in the pst is simply imitate, but new reconstitution is done by using the elements in the past. at the same time, ti was clarified that even though the elements in the past are revived as they were, dress and its ornament is governed by the social and cultural environments of he day, and with this proof it can be said that the fashion in each age is of a reflection of social phenomena of that age.

• Journal of the Korean Institute of Gas
• /
• v.20 no.6
• /
• pp.9-15
• /
• 2016

Liquefied petroleum gas (LPG) and compressed natural gas (CNG) are often used as fuel for vehicles because they are clean alternative gas fuels. CNG, as a low-carbon fuel, can contribute to the reduction of greenhouse gas emissions. LPG is often used as fuel for taxis because the performance is almost the same as that of gasoline but the price is lower. In the present study, the exhaust gas and the particle number (PN) of particulate matter, which is a recent environmental issue, were compared between LPG and CNG for the same vehicle. A chassis dynamometer was used to conduct the test according to the Federal Test Procedure (FTP)-75 and Worldwide harmonized Light-duty vehicle Test Procedure (WLTC) modes. The PN values of discharged particles having sizes of 5 nm or larger and 23 nm or larger were measured using two condensation particle counters (CPC). The ratio of carbon dioxide was high in the exhaust gas from the LPG vehicle; the ratio of methane was high in the exhaust gas from the CNG vehicle. The PN values of the emitted particles from the two fuels were similar. The PN values of particles having sizes of 23 nm or smaller were high in the high-speed WLTC mode.

• Clinics in Shoulder and Elbow
• /
• v.20 no.3
• /
• pp.133-137
• /
• 2017

Background: To determine the natural progression of conservatively treated rotator cuff tears, we evaluated changes in radiologic and clinical parameters in patients whose recalcitrant tears were neglected after conservative treatment. Methods: A total of 73 patients with recalcitrant rotator cuff tears in spite of conservative treatment were included in this study. We measured changes in tear size and in the extent of fatty infiltration of the rotator cuff by comparing the initial and final follow-up magnetic resonance imagings (MRIs). To determine factors influencing the change in tear size, we collected the medical history of patients taken at the time of initial admission. Results: The average follow-up period was 20.1 months, and the average increase in tear size across this period was 6.2 mm. In terms of steroid injection, we found that the increases in tear size of the steroid injection group (p=0.049) and of the sub-group that had received more than three steroid injections (p=0.010) were significantly greater than that of the non-steroid injection group. Conclusions: We found that the increase in cuff tear size was on average 6.2 mm across the follow-up period, indicating that neglecting cuff tears may cause them to progress into more severe tears. We also observed that a history of steroid injection might be a possible risk factor for a worse prognosis of cuff tears. Therefore, we suggest that patients with rotator cuff tears and a history of steroid injection are recommended aggressive modes of treatment such as surgery.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.6
• /
• pp.766-777
• /
• 1997

The purpose of this study was to investigate inheritance modes of low temperature germinability(LTG) on rice. Two experiments were carried out: In experiment I, the seeds of 10 rice varieties yielded at the different cultivation conditions which were transplanted in a paddy field from May 20 to July 5 with 15-day interval, were tested at fixed temperature (13$^{\circ}C$) in-door and at field with natural conditions to find out the change of LTG according to different cultivating condition among the each variety, In experiment II, F$_1$ seeds of full diallal cross from six parents, were analyzed for combining ability and reciprocal differences of low temperature germinability. The results are summarized as follows. The seeds of 10 varieties showed significant differences of LTG at the different cultivation conditions, varieties and their interaction. And the relationship between LTG coefficient at 13$^{\circ}C$ and low temperature emergence(LTE) coefficient at field was highly significantly positive(r=0.511). From the analysis of the diallel cross, high significance was found at reciprocal difference and alpha inheritance. The mean squares of general combining ability(GCA) and specific combining ability of LTG were highly significant with higher mean squares of GCA. Seventeen out of 30 cross combinations showed transgressive segregation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.1
• /
• pp.409-416
• /
• 2020

The seismic performance of a containment structure should be secured to maintain the structural soundness of a containment structure under various earthquakes that occur globally. Therefore, an analysis of the seismic performance of a modular containment structure for a small modular reactor is also required. To analyze the seismic performance of modular containment, FEM models with contact surfaces between the modules and tendon were prepared and the modal and seismic analyses were performed. The displacement, stress, and gap size of modular containment under earthquake wave were analyzed. The effects of the tendon force, friction coefficient, and earthquake wave on the seismic performance were analyzed. The seismic performance of monolithic containment was also analyzed for comparison. In the 1st and 2nd natural modes, which most likely affect, the modular containment showed horizontal dynamic behavior, which is similar to monolithic containment, because of the combined effects of the tendon force and friction force between modules. When the combined effect is sufficient, the seismic performance of the modular containment is secured over a certain level. An additional increase in seismic performance is expected when some material with a larger friction coefficient is adopted on the contact surface.

• Korean Journal of Remote Sensing
• /
• v.26 no.2
• /
• pp.123-131
• /
• 2010

In this paper we applied Ground-Based Synthetic Aperture Radar(GB-SAR) interferometry to detect artificial displacement of a reflector and performed an atmospheric humidity correction to improve the accuracy. A series of GB-SAR images were obtained using a center frequency of 5.3 GHz with a range resolution of 25 cm and a azimuth resolution of $0.324^{\circ}$, all in full-polarization (HH, VV, VH, HV) modes. A triangular trihedral corner reflector was located 160 m away from the system, and the artificial displacements of 0-40 mm was implemented during the GB-SAR image acquisition. The result showed that the RMS error between the actual and measured displacements, averaged in all polarization data, was 1.22 mm, while the maximum error in case of the 40 mm displacement was 2.72 mm at HH-polarization. After the atmospheric correction with respect to the humidity, the RMS error was reduced to 0.52 mm. We conclude that a GB-SAR system can be used to monitor the possible displacement of artificial/natural scatterers and the stability assessment with sub-millimeter accuracy.

• Journal of Life Science
• /
• v.31 no.4
• /
• pp.430-441
• /
• 2021

Sesquiterpene lactones (STLs) are terpenoids found mostly in the Asteraceae family and are known for their strong cytotoxic properties, among other notable bioactivities. Some STLs, such as artemisinin and mipsagargin, are already commercially available and are used to fight malaria and tumor growth, respectively. Although the interest in STLs was low for a time after their discovery due to their toxic nature, past decades have witnessed a soar in STL-based studies focused on developing novel pharmaceuticals via chemical diversification. These studies have reported several promising physiological effects for STLs, including lower toxicity and diverse modes of action, and have demonstrated the antimicrobial, antioxidant, hepatoprotective, antiviral, antiprotozoal, phytotoxic, antitumor, and antiaging properties of STLs. STLs are mainly considered as valuable natural molecules for the fight against cancer since most STLs induce death of different types of cancer cells, as shown by in vitro and in vivo studies. Some STLs can also enhance the effects of drugs that are already in clinical use. Medicinal chemists use various STLs as starting molecules for the synthesis of new STLs or different bioactive compounds. All these developments warrant future research to provide more information on STLs, their bioactivities, and their mode of action. In this context, this review has summarized the bioactivities of some of the widely studied STLs, namely artemisinin, costunolide, thapsigargin, arglabin, parthenolide, alantolactone, cynaropicrin, helenalin, and santonin.