• Land and Housing Review
• /
• v.2 no.2
• /
• pp.163-170
• /
• 2011

Individual Vacuum Pressure Method (IVPM) is a soft ground improvement technique, in which a vacuum pressure can be directly applied to the vertical drain board to promote consolidation and to strengthen the soft ground. This method does not require surcharge loads, different to embankment or pre-loading method. In this study, the ground improvement efficiency of Individual Vacuum Pressure Method was estimated when suction pressure increases step by step(-20, -40, -60, -80kPa) with different periods. During Individual Vacuum Pressure Method process, surface settlement and pore pressure were monitored, and cone resistance as well as water content were also measured after the completion of Individual Vacuum Pressure Method treatment. From the results, optimum duration of each step of vacuum pressure was determined, and the settlement was calculated using FEM numerical analysis.

• Korean Journal of Food Science and Technology
• /
• v.42 no.1
• /
• pp.45-49
• /
• 2010

To reduce the astringent taste of lotus root, the effects of various treatment methods such as drying, soaking, steaming and roasting on the physicochemical properties and sensory characteristics were investigated. The following process conditions were selected: 1) drying (D), 2) soaking followed by drying ($SK{\rightarrow}D$), 3) steaming followed by drying ($ST{\rightarrow}D$), 4) drying followed by roasting ($D{\rightarrow}R$), 5) soaking and then drying followed by roasting ($SK{\rightarrow}D{\rightarrow}R$), 6) steaming and then drying followed by roasting ($ST{\rightarrow}D{\rightarrow$}. The tannin content of the lotus root was lowest when it was treated by steaming followed by drying ($ST{\rightarrow}D$). The astringent taste of lotus root was reduced by steaming, and the roasted taste was improved by roasting in terms of sensory and flavor characteristics. Consequently, lotus root treated by steaming and then drying followed by roasting ($ST{\rightarrow}D{\rightarrow}R$) showed the highest preference with respect to astringent and roasted taste.

• Korean Journal of Food Science and Technology
• /
• v.30 no.1
• /
• pp.42-48
• /
• 1998

Physicochemical properties of waxy maize starch and oxidized waxy maize starch with sodium hypochlorite $(0{\sim}60\;mg\;CL_2/g\;starch,40^{\circ}C,\;pH\;10,\;3.0\;hr)$ were studied. As sodium hypochlorite concentration was increased, the content of crude lipid and crude protein of the oxidized starch were decreased. And crude protein content and whiteness was considered to show negative regression. However, the crude ash content of the oxidized starch increased significantly with oxidation and bore a positive regression to the chlorine content. There was a progressive increase in the carboxyl content with increasing oxidant level. After pasting in hot water and cooling, viscosity of the oxidized starches were drastically lower than that of native starch . As carboxyl contents of the oxidized starch increased, the solubility and swelling power was increased. When waxy maize starch treated with 0, 1.5, 3.0 and 6.0% sodium hypochlorite, temperature of initial gelatinization of oxidized starch was shown to 65, 65, 60 and $50^{\circ}C$, respectively. The oxidized waxy maize starches also form clearer pastes. Water binding capacity of the oxidized starch decreased as the degree of carboxyl group substitution increased. Waxy maize starch has polygonal and some round granules which range from about 3.7 to $20\;{\mu}m$ in diameter. Surface appearance of the waxy maize starch became rough when oxidized with sodium hypochlorite. When homogenate of the oxidized waxy maize starch solution and corn germ oil was stored under room temperature for 24 hours, the emulsion stability was considered to depend on starch concentration and degree of substitution.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.41 no.3
• /
• pp.219-227
• /
• 2015

This study was conducted to determine 10 preservatives (benzyl alcohol (BAl), phenoxyethanol (PE), benzoic acid (BA), sorbic acid (SA), methyl paraben (MP), ethyl paraben (EP), propyl paraben (PP), isopropyl paraben (IPP), butyl paraben (BP), isobutyl paraben (IBP)) levels in 125 cosmetics (n = 125) for children by the simultaneous analysis of HPLC. The detection ranges were as follows; 0.01 ~ 0.91% (n = 35) for PE, 0.01 ~ 0.48% (n = 28) for BA, 0.01 ~ 0.78% (n = 9) for BAl, 0.01 ~ 0.11% (n = 3) for SA, 0.04 ~ 0.21% (n = 8) for MP, 0.02 ~ 0.09% (n = 8) for PP, and 0.04% (n = 1) for EP. The order of detection rates was cleanser (63%) > cream (48%) > sunscreen (46%) > lotion (38%) > oil (13%). At least one of target preservatives was contained in 50% (63/125) of samples and the content of the detected preservatives was within maximum allowed amount established by KFDA. Phenoxyethanol and benzoic acid were used more frequently than paraoxybenzoate esters (parabens) in cosmetics for children and the detected parabens was mainly the mixture of methyl paraben and propyl paraben.

• Korean Journal of Veterinary Research
• /
• v.39 no.6
• /
• pp.1119-1125
• /
• 1999

Since Robert Koch found tubercle bacilli in 1882, the studies on tubercle bacilli of human and animal had been carried out. Being old tuberculin(OT) introduced in 1890, the specificity of the diagnosis of tuberculosis has been improved by continual uses of heat concentrated synthetic medium(HCSM) and purified protein derivatives(PPD) tuberculin. Now, two types of tuberculin test are used worldwidly ; the single intradermal test(SIT) using bovine tuberculin and the single intradermal comparative tuberculin test(SICTT) using avian and bovine tuberculins. In the SICTT, each countries have used with different combination of both avian and bovine tuberculins' titers. However, this kinds of studies have not reported in Korea. Therefore, the studies on the combination of their tuberculins' titers were performed through intradermal test of guinea pigs sensitized with either Mycobacterium bovis or M avium and were examined in 10 cattles of SIT positive reactors. Also, IFN-${\gamma}$ assay, the latest diagnostic method of bovine tuberculosis, was experimentally applied to SIT positive reactors. For determining the optimal titers, sensitized guinea pigs with M bovis and M avium were intradermally injected avian and bovine tuberculin. In guinea pigs sensitized with M bovis, bovine tuberculin 50 T.U. showed significant difference from all tested concentrations of avian tuberculin(p < 0.05). In guinea pigs sensitized with M avium, there is significantly different between bovine tuberculin and avian tuberculin by 25 T.U.(p < 0.01). Therefore, optimal titers of bovine and avian PPD tuberculins' titers for the SICTT in Korea were 5,000 and 2,500 tuberculin units, respectively, and the swelling diffences between bovine and avian site in SIT positive reactors were above 3mm. Also, in IFN-${\gamma}$ assay, the 9 SIT positive reactors were showed all the positive reactions.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.5 no.3
• /
• pp.210-219
• /
• 2005

We report on a low-cost V-band wireless transceiver with no use of any local oscillator in the receiver block using a self-heterodyne architecture. V-band millimeter-wave monolithic IC (MMIC) modules were developed to demonstrate the wireless transceiver using coplanar waveguide (CPW) and GaAs PHEMT technologies. The MMIC modules such as the MMIC low noise amplifier (LNA), medium power amplifier (MPA) and the up/down-mixer were installed in the transceiver system. To interface the MMIC chips with the component modules for the transceiver system, CPW-to-waveguide fin-line transition modules of WR-15 type were designed and fabricated. The fabricated LNA modules showed a $S_{21}$ gain of 8.4 dB and a noise figure of 5.6 dB at 58 GHz. The MPA modules exhibited a gain of 6.9 dB and a $P_{1dB}$ of 5.4 dBm at 58 GHz. The conversion losses of the up-mixer and the down-mixer module were 14.3 dB at a LO power of 15 dBm, and 19.7 dB at a LO power of 0 dBm, respectively. From the measurement of V-band wireless transceiver, a conversion gain of 0.2 dB and a $P_{1dB}$ of 5.2 dBm were obtained in the transmitter block. The receiver block showed a conversion gain of 2.1 dB and a $P_{1dB}$ of -18.6 dBm. The wireless transceiver system demonstrated a successful data transfer within a distance of 5 meters.

• The Korean Journal of Malacology
• /
• v.31 no.2
• /
• pp.129-136
• /
• 2015

To introduce an oyster rack culture in tidal flat of Wando-gun, Korea, we investigated sanitary conditions from 2012 April to 2013 March in oyster growing waters and adjacent area in Wando. Average seawater temperature and salinity ranged $8.6-28.0^{\circ}C$ and 26.2-33.6 psu, respectively. The coliform group and fecal coliform of seawater ranged < 1.8-13.0 MPN/100 mL each. Only one of 60 samples was exceeded in the European criteria of fecal coliform. Influence of adjunct basin's pollution load on cultural waters was negligible, which half radius of dilution was not above 300 m. According to our observation, however, landing of oyster should be banned for at least 5 days after the heavy rainfall. Our findings meet the sanitary seawater criteria for domestic use and export of shellfish and classified as 'Class A' in European Community regulations for bivalve culture.

• Food Science and Preservation
• /
• v.14 no.6
• /
• pp.578-583
• /
• 2007

This study was conducted to evaluate the effect of high $CO_2$ pre-storage treatment on the quality of tomatoes (Lycopersicon esculentum Mill.) during ripening. Tomatoes at different maturity stage of breaker and pink were treated in air, or $CO_2$ (25, 50, 100%) for 24 hr at $20^{\circ}C$ before ripening in air at $20^{\circ}C$. Change of surface colour and softening were reduced by high $CO_2$ treatment of all concentrations. This effect of $CO_2$ on the colour and softening was higher in breaker fruit than pink fruit. $CO_2$ concentration of $25{\sim}100%$ did not affect on soluble solids content during ripening period. Titratable acidity of breaker tomatoes were reduced by 100% $CO_2$ treatment. High $CO_2$ treatment slightly reduced sweetness of breaker tomatoes. Acidity and texture of tomatoes increased with high $CO_2$ treatment. Off-flavour was denoted by $CO_2$ treatment in pink tomatoes. The external $CO_2$ injury developed after 22 days at $20^{\circ}C$ in pink tomatoes when treated with ${\geq}25%$ $CO_2$ and in breaker tomatoes with ${\geq}50%$ $CO_2$.

• Journal of Digital Convergence
• /
• v.15 no.7
• /
• pp.111-121
• /
• 2017

Smartphone use has become a part of everyday life, not only for adolescents but also for elderly and older people. Thus, this study explored the effect of demographic variables, the amount of smartphone usage, type of smartphone use and psychosocial variables on smartphone dependence of the elder group. We analyzed the data of 5627 (50s and 60s) of the Internet overdependence survey data of the Korea Information Society Agency in 2016. As a result of hierarchical multiple regression analysis, More frequency of smartphone use of weekday and weekend, and usage time of smartphone of weekday were related to greater smartphone dependence. More smartphone use for information seeking and games were associated with greater smartphone dependence. And, as loneliness and anxiety increased, smartphone dependence increased, while smartphone dependence decreased, as social capital increased. Through this study, it is necessary to understand characteristics related to smartphone dependence of elder and older group, and to use this knowledge to solve their smartphone dependence. Future studies also need to identify the causal relationship between predictors of smartphone dependence in elderly and older people.

• Food Science and Preservation
• /
• v.22 no.1
• /
• pp.145-153
• /
• 2015

To investigate the hypoglycemic effect of the submerged culture of the Ceriporia lacerata mycelium (CL01) species, in-vitro and in-vivo tests were executed using INS-1 and 3T3-L1 cells, normal and diabetic mice. CL01 exhibited an inhibitory effect on cell death through dexamethasone in the INS-1 cells, and increased the GLUT4 expression in the 3T3-L1 cells. A hematological monitoring test was executed using diabetic mice divided into four groups : normal control (G1), negative control (G2), positive control (G3), and CL01 250 mg/kg (G4) groups, which were fed daily for 6 weeks. The body weight gain, food intake, and water intake of G4 were not significantly different from those of G2. After 5 weeks, the blood glucose levels of G4 were significantly different from those of G2. After 6 weeks, the plasma insulin levels of G4 increased by about 36% compared to those of G2, and the plasma C-peptide levels of G4 were lower by about 18%. than those of G3. The results of the oral glucose tolerance test (OGTT) showed that CL01 lessened the blood glucose levels of G4 by 15% compared to G2. It was concluded that CL01 stimulates the proliferation of beta cells and promotes insulin secretion and may thus have a potential in improving the hypoglycemic effects among the diabetic symptoms.