• The Journal of Engineering Geology
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• v.25 no.3
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• pp.357-368
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• 2015

Brittle failure of Mesozoic granite in the Daejeon region is predicted using empirical analysis and numerical modeling techniques. The input parameters selected for these techniques were based on the results of laboratory tests, including damage-controlled tests. Rock masses that were considered to be strong during laboratory testing were assigned to "group A" and those considered to be extremely strong were assigned to "group B". The properties of each group were then used in the analyses. In-situ stress measurements, or the ratio of horizontal to vertical stress (k), were also necessary for the analyses, but no such measurements have been made in the study area. Therefore, k values of 1, 2, and 3 were assumed. In the case of k=1, empirical analysis and numerical modeling show no indication of brittle failure from the surface to1000 m depth. When k=2, brittle failure of the rock mass occurs at depths below 800 m. For k=3, brittle failure occurs at depths below 600 m. Although both the Cohesion Weakening Friction Strengthening (CWFS) and Mohr-Coulomb models were used to predict brittle failure, only the CWFS model performed well in simulating the range and depth of the brittle failure zone.

• Reproductive and Developmental Biology
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• v.34 no.2
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• pp.89-94
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• 2010

Melatonin is induced by light information through the retina and leads to growth factor activation. Thus, we investigated the effects of melatonin by controlling the photoperiod of growing young rats. Male Sprague-Dawley rats (n=6; 4 weeks old) were divided into two experimental groups: the L/D group (normal photoperiod; light/dark: 12/12 h; lights on at 9:00 a.m.) and the L/L group (light/light: 24 h). Rat body weight and food consumption were measured daily for 8 weeks. After 8 weeks, the rats were anesthetized with a mixture of ketamine (50 mg/kg) and xylazine (10 mg/kg) and sacrificed. Tissue was then collected for RNA isolation (from brain, heart, liver, kidney, adrenal gland, testis, tibia, hind limb muscles). Also, serum was isolated from blood using a centrifugal separation. The L/L group had significantly lower body weight than the L/D group from 4 to 6 weeks (p<0.05). The L/D group had increased tissue mass, compared with the L/L group, but the difference was not statistically significant. The L/D group had a significantly higher melatonin concentration than the L/L group between the hours of midnight and 2:00 a.m (p<0.01). These results indicate that photoperiod length may affect the secretion of melatonin from the pineal gland. Also, the reduction of nocturnal melatonin secretion may retard the development of growing young rats. In future studies, we plan to compare exogenous melatonin administration with endogenous melatonin concentration induced by photoperiod control. Moreover, we will confirm whether the effects seen in pathological animal models can be reversed by controlling the photoperiod.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.3
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• pp.226-232
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• 1988

Non-enzymatic browning is a carbohydrate dehydration reaction, accelerated thorough the interaction of amino compounds. Reaction depends on several factors including temperature, reactant concentration, pH, water activity and specific ion concentrations, and result in progressive development of brown pigments in the affected food systems. The present study was designed to utilize a kinetic approach to analyze the effect of temperature and water activity on the browning development in green ten. The green tea was controlled at aw of 0.33, 0.44, 0.52 and 0.65 using saturated salt solutions and then stored at 35,45 and $55^{\circ}C$. Author portion of the sample of which the water activities were controlled in the same manner was stored at 35 and $55^{\circ}C$ alternately with 7 days interval. Simplified kinetic models were used to obtain the various kinetic parameters for browning development in green tea subjected to accelerated shelf-life tests(ASLT). The reaction of browning development was zero order. The activation energies calculated from Arrhenius plot ranged $1.5{\sim}2.4kcal/mole$ and $Q_{10}$ values were between 1.07 and 1.12. These kinetic parameters were then used to predict browning development under the nonsteady storage. Assessed from the parameters the shelf-lives at $25^{\circ}C$, the time to reach 1.02 O.D./g solid at which severe brown color change could be detectable, ranged 57 to 113 days and showed decrease with increase in aw. The predicted shelf-lives at different water activities were a little higher than actual values.

• Journal of Cardiovascular Imaging
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• v.30 no.3
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• pp.153-168
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• 2022

Recent studies have shown that sodium/glucose cotransporter 2 (SGLT2) inhibitors might exert favourable changes on cardiac parameters as observed on cardiovascular imaging. We conducted a systematic review and meta-analysis to determine the effects of SGLT2 inhibitors on cardiac imaging parameters. Four electronic databases (PubMed, Embase, Cochrane, Scopus) were searched for studies in which the effects of SGLT2 inhibitors on cardiac imaging parameters were examined. Studies in which a population was administered SGLT2 inhibitors and analysed by echocardiography and/or cardiac magnetic resonance (CMR) imaging were included. Random-effects pair-wise meta-analysis models were utilized to summarize the studies. A total of 11 randomized controlled trials was included with a combined cohort of 910 patients. Comparing patients receiving SGLT2 inhibitors with subjects receiving placebo, the mean change in CMR-measured left ventricular mass (LVM) was -3.87 g (95% confidence interval [CI], -7.77 to 0.04), that in left ventricular end-systolic volume (LVESV) was -5.96 mL (95% CI, -10.52 to -1.41) for combined LVESV outcomes, that in left atrial volume index (LAVi) was -1.78 mL/m² (95% CI, -3.01 to -0.55) for combined LAVi outcomes, and that in echocardiography-measured E/e' was -0.73 (95% CI, -1.43 to -0.03). Between-group differences were not observed in LVM and LVESV after indexation. The only between-group difference that persisted was for LAVi. Treatment with SGLT2 inhibitors resulted in reduction in LAVi and E/e' on imaging, indicating they might have an effect on outcomes associated with LV diastolic function.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.6 s.312
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• pp.34-42
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• 2006

As art analytic method to uncover interesting patterns hidden under a large volume of data, data mining research has been actively done so far in various fields. However, current state-of-the-arts in data mining research have several challenging problems such as being too ad-hoc. The existing techniques are mostly the ones designed for individual problems, so there is no unifying theory applicable for more general data mining problems. In this paper, we address the problem of classification, which is one of significant data mining tasks. Specifically, our objective is to evaluate radial basis function (RBF) model for classification tasks and investigate its usefulness. For evaluation, we analyze the popular Monk's problems which are well-known datasets in data mining research. First, we develop RBF models by using the representational capacity based learning algorithm, and then perform a comparative assessment of the results with other models generated by the existing techniques. Through a variety of experiments, it is empirically shown that the RBF model has not only the superior performance on the Monk's problems but also its modeling process can be controlled in a systematic way, so the RBF model with RC-based algorithm might be a good candidate to handle the current ad-hoc problem.

• Journal of the Korean Geographical Society
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• v.30 no.2
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• pp.120-131
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• 1995

To analyze mobility patterns, this study used three Constraint (Capability Constraint, Coupling Constraint, Authority Constraint) models which were proposed in Dr. Hagerstrand's Time-space theory. This paper shows that three constraint models have some effects upon mobility by age. In this study, Capability Constraint means a certain special constraint that is what we can't do during proceeding basic natural urges like sleep, fare, etc. Coupling constraint is a physical one. Each person limits the action range for staying on a special place in special time. For instance, students have to stay in school so that they have mobility constraints. Authority Constraint is a social one. When we use urban facilities or traffic, we may be controlled by mobility sphere by an agreement or a social position. It is social agreement that the opening hour of a store, the time table of mass-transportation and a social positional control that the personal income, the standard of education. In this study it has been in a process of determination of the cluster number that degree of influences a social constraint to mobility. Considering the mobility constraint of characteristics of space divides urban and rural, people in urban area have higher mobility rate than in rural area. Resuets of determination of the cluster, show similar mobility pattern. People in urban area are connected verity of mobility which related to urban space structures with determination of cluste-number. That is to say, mobility patterns can be changed by space charactcristics. Constraints by sex and age are also social constraints and they are influenced by mobility patterns. For instance, females at the age of twenties have similar mobility pattern to the same age male but they have sudden changes after thirty's age. Male entertains a similar pattern without restriction of age. That is to say, management by sex as a social constraint affects mobility. To establish more realistic traffie policy, mobility formation should be reflected to the space in a view of social-behavioral science. To embody this, some problems should be investigated as follows. 1. As a problem of methodology, if sufficient samples ensured, we could subdivide clusters and could open up a new method of analyzing the mobility clusters by using the neuro-network. 2. Extracting actions connected with mobility and finding life cycle which is classified by daily cluste-characteristics, suitable counterproposal could be presented to the traific policy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.195-201
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• 2001

Sowing date experiments were carried out by employing a rice variety "Kwanganbyeo" in both field and phytotron with natural daylength. In phytotron, temperatures were controlled at daily mean of 21$^{\circ}C$ and 24$^{\circ}C$. The responses of final leaf number and beading date were analyzed in relation to daylength during photo-sensitive period (PSP). Based on the component models predicting the final leaf number and leaf appearance rate, a rice phenology model was established and verified. Days from sowing to flowering (DSF) were shortened and final number of leaves (FNL) increased as sowing dates were delayed from 25 April to 5 June in field and phytotron. The increased leaf appearance rate (LAR) and the reduced FNL, respectively, due to the higher temperature and the shorter daylength in delayed sowings in the field brought about greater shortening of DSF than in the phytotron where only FNL was reduced by shorter daylength in delayed sewings. FNL showed very close relationship with the average daylength during PSP of six-leaf stage to panicle initiation, being well fitted to the following rational function ($R^2$=0.98):(equation omitted) where D is daylength and a, b, and c are the constants that were estimated as 14.694, -0.992, and -0.068 in Kwanganbyeo, respectively. The rice phonology model, which was composed of two component models for LAR and FNL, predicted DSF very accurately. The differences between the observed and predicted DSF was less than two days in the sewing date field experiments in 1999 and 2000 of which data were not used for the model construction.struction.

• Journal of Acupuncture Research
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• v.34 no.4
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• pp.153-158
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• 2017

Background: Hominis placenta (HP) is used in Korean medicine to tonify qi and blood, and enrich yin and tonify yang. HP has been reported to have therapeutic effects. Methods: A survey of international and Korean electronic databases was conducted using the search terms "hominis placenta pharmacopuncture" and "hominis placenta extract". The search was limited to material published up to May 31, 2017. Results: A total of 83 studies were included in this systematic review: 50 were clinical studies, 25 were basic studies, and 8 were other types of study. Among clinical studies, the most frequently treated disease groups were musculoskeletal diseases and nervous system diseases. In vitro studies were conducted mainly on anti-inflammatory, analgesic, and anti-cell necrosis models. Most of the in vivo studies were performed in rheumatoid arthritis or diabetic complications models. Conclusion: HP pharmacopuncture has effects in the treatment of various diseases. Further large-scale randomized controlled trials are needed to improve the level of evidence for HP pharmacopuncture. It would be helpful if future in vitro and in vivo studies could identify the mechanism of action of HP pharmacopuncture.

• Journal of Astronomy and Space Sciences
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• v.21 no.2
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• pp.141-152
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• 2004

Optics fabrication process for precision space optical parts includes bound abrasive grinding, loose abrasive lapping and polishing. The traditional bound abrasive grinding with bronze bond cupped diamond wheel leaves the machine marks of about $20{mu}m$ rms in height and the subsurface damage of about 1 ${mu}m$ rms in height to be removed by subsequent loose abrasive lapping. We explored an efficient quantitative control of precision CNC grinding. The machining parameters such as grain size, work-piece rotation speed and feed rate were altered while grinding the work-piece surfaces of 20-100 mm in diameter. The input grinding variables and the resulting surface quality data were used to build grinding prediction models using empirical and multi-variable regression analysis. The effectiveness of such grinding prediction models was then examined by running a series of precision CNC grinding operation with a set of controlled input variables and predicted output surface quality indicators. The experiment achieved the predictability down to ${pm}20$ nm in height and the surface roughness down to 36 nm in height. This study contributed to improvement of the process efficiency reaching directly the polishing and figuring process without the need for the loose abrasive lapping stage.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.181-186
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• 2011

To predict the bud bursting date of 'Campbell Early' grapevines, the bud developmental rate (DVR) models were constructed. The DVRs for bud bursting were calculated from the demanded times at controlled air temperatures. The DVRs were examined on the 'Campbell Early' grapevines incubated in three different temperatures at 4.6, 11.8, and $16.6^{\circ}C$. The DVR increased exponentially or linearly on the air temperature with a slope of about 0.0019. The DVR equations were computed as $DVR=0.0249+0.0020e^{0.1654x}$ or DVR = 0.0019x + 0.0187. These DVR equations offered developmental indices and predicted dates for bud bursting with air temperature data. The DVR equations were validated to the bud bursting data observed in the field. When bud bursting dates were calculated with daily temperature data, the root mean squared error (RMSE) between the observed and the predicted dates was less than 4 days. When those were calculated with hourly temperature data, on the other hand, the RMSE was less than 3 days. These results suggest that the DVR models are useful to predict bud bursting date of 'Campbell Early' grapevines.