• Journal of Korean Society of Transportation
• /
• v.17 no.1
• /
• pp.29-39
• /
• 1999

An earlier study of the effect of rain found that the capacity of freeway systems was reduced, but did not address the effects of rain on the nature of traffic flows. Indeed, the substantial variation due to the intensity of adverse weather conditions is entirely rational so that its effects must be considered in freeway facility design. However, all of the data in Highway Capacity Manual(HCM) have come from ideal conditions. The primary objective of this study is to investigate the effect of rain on urban freeway traffic flows in Seoul. To do so, the relations between three key traffic variables(flow rates, speed, occupancy), their threshold values between congested and uncontested traffic flow regimes, and speed distribution were investigated. The traffic data from Olympic Expressway in Seoul were obtained from Imagine Detection System (Autoscope) with 30 seconds and 1 minute time periods. The slope of the regression line relating flow to occupancy in the uncongested regime decreases when it is raining. In essence, this result indicates that the average service flow rate (it may be interpreted as a capacity of freeway) is reduced as weather conditions deteriorate. The reduction is in the range between 10 and 20%, which agrees with the range proposed by 1994 US HCM. It is noteworthy that the service flow rates of inner lanes are relatively higher than those of other lanes. The average speed is also reduced in rainy day, but the flow-speed relationship and the threshold values of speed and occupancy (these are called critical speed and critical occupancy) are not very sensitive to the weather conditions.

• Korean Journal of Agricultural Science
• /
• v.13 no.1
• /
• pp.113-122
• /
• 1986

In order to promote mechanization of corn harvesting in Korea, this study was conducted to find out the effect of moisture content on compressive properties such as force, deformation, energy and modulus of stiffness to the bioyield and the rupture point for Korean corn kernel. In this study, the loading positions of corn were flat, edge, longitude and the moisture contents were about 13, 17, 21, 25% in wet basis. The compression test was carreied out with flat plate by use of dynamic straingage for three varieties of Korean corn under quasi-static force when the loading rate was 1.125mm/min. The results of this study are summarized as follows; 1. When the moisture content of corn ranged from 12.5 to 24.5 percent, at flat position, the bioyied force was in the range of 13.63-26.73 kg and the maximum compressive strength was in the range of 21.55-47.65kg. Their values were reached minimum at about 17% and maximum at about 21% moisture content. The bioyield force was in the range of 13.58-6.70kg at edge position and the maximum compressive strength which was 16.42 to 7.82kg at edge position was lower than that which was 18.55-9.05kg at longitudinal position. 2. Deformation of corn varied from 0.43 to 1.37 mm at bioyield point and from 0.70 to 2.66mm at rupture point between 12.5 to 24.5% moisture content. As the moisture content increased, deformation was increased. 3. The moduli of resilience and toughness of corn ranged from 2.60 to 8.57kg. mm and from 6.41 to 34.36kg. mm when the moisture content ranged from 12.5 to 24.5 percent, respectively. As the moisture content increased, the modulus of toughness was increased at edge position and decreased at longitudinal position. And their values were equal each other at 22-23% moisture content. 4. The modulus of stiffness was decreased with increase in the moisture content. Its values ranged from 32.07 to 5.86 kg/mm at edge position and from 42.12 to 18.68kg/mm at flat position, respectively. Also, the values of Suweon 19 were higher than those of Buyeo. 5. It was considered that the compressive properties of corn at flat position were more important on the design data for corn harvesting and processing machinery than those of edge or longitudinal position. Also, grinding energy would be minimized when a corn was processed between about 12.5 to 17% moisture content and corn damage would be reduced when a corn was handled between about 19 to 24% moisture content in wet basis.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.9 no.1
• /
• pp.1-13
• /
• 2006

A field survey on the spatio-temporal distribution characteristics and origins of organic matter in surface sediments was carried out monthly at six stations in Gamak Bay, South Korea from April 2000 to March 2002. The range of ignition loss(IL) was $4.6{\sim}11.6%(7.1{\pm}1.6%)$, while chemical oxygen demand(CODs) ranged from $12.25{\sim}99.26mgO_2/g-dry(30.98{\pm}19.09mgO_2/g-dry)$, acid volatile sulfide(AVS) went from no detection(ND)${\sim}10.29mgS/g-dry(1.02{\pm}0.58mgS/g-dry)$, and phaeopigment was $6.84{\sim}116.18{\mu}g/g-dry(23.72{\pm}21.16{\mu}g/g-dry)$. The ranges of particulate organic carbon(POC) and particulate organic nitrogen(PON) were $5.45{\sim}23.24 mgC/g-dty(10.34{\pm}4.40C\;mgC/g-dry)$ and $0.71{\sim}2.99mgN/g-dry(1.37{\pm}0.58mgN/g-dry)$, respectively. Water content was in the range of $43.1{\sim}77.6%(55.8{\pm}5.6%)$, and mud content(silt+clay) was higher than 95% at all stations. The spatial distribution of organic matter in surface sediments was greatly divided between the northwestern, central and eastern areas, southern entrance area from the distribution characteristic of their organic matters. The concentrations of almost all items were greater at the northwestern and southern entrance area than at the other areas in Gamak Bay. In particular, sedimentary pollution was very serious at the northwestern area, because the area had an excessive supply of organic matter due to aquaculture activity and the inflow of sewage from the land. These materials stayed longer because of the topographical characteristics of such as basin and the anoxic conditions in the bottom seawater environment caused by thermocline in the summer. The tendency of temporal change was most prominently in the period of high-water temperatures than low-water ones at the northwestern and southern entrance areas. On the other hand, the central and eastern areas did not show a regular trend for changing the concentrations of each item but mainly showed a higher tendency during the low-water temperatures. This was observed for all but AVS concentrations which were higher during the period of high-water temperature at all stations. Especially, the central and eastern areas showed a large temporal increase of AVS concentration during those periods of high-water temperature where the concentration of CODs was in excess of $20mgO_2/g-dry$. The results show that the organic matters in surface sediments in Gamak Bay actually originated from autochthonous organic matters with eight or less in average C/N ratio including the organic matters generated by the use of ocean, rather than terrigenous organic matters. However, the formation of autochthonous organic matter was mainly derived from detritus than living phytoplankton, indicated the results of the POC/phaeopigment ratio. In addition, the CODs/IL ratio results demonstrate that the detritus was the product of artificial activities such as dregs feeding and fecal pellets of farm organisms caused by aquaculture activities rather than the dynamic of natural ocean activities.

• Journal of Technology Innovation
• /
• v.14 no.1
• /
• pp.31-66
• /
• 2006

The country with a relative abundance of human capital conducts relatively more R&D in the steady state than its partner. This country acquires the know-how to produce a relatively wider range of innovative goods. High technology comprises a large share of the national economy in the human-capital rich country and real output growth is faster. This prediction would seem to accord weakly with empirical observation of Korean economy.

• Korean Journal of Clinical Laboratory Science
• /
• v.49 no.2
• /
• pp.79-87
• /
• 2017

GenesWell$^{TM}$ BCT is a 12-gene test suggesting the prognostic risk score (BCT Score) for distant metastasis within the first 10 years in early breast cancer patients with hormone receptor-positive, HER2-negative, and pN0~1 tumors. In this study, we validated the analytical performance of GenesWell$^{TM}$ BCT. Gene expression values were measured by a one-step, real-time qPCR, using RNA extracted from FFPE specimens of early breast cancer patients. Limit of Blank, Limit of Detection, and dynamic range for each of the 12 genes were assessed by serially diluted RNA pools. The analytical precision and specificity were evaluated by three different RNA samples representing low risk group, high risk group, and near-cutoff group in accordance with their BCT Scores. GenesWell$^{TM}$ BCT could detect gene expression of each of the 12 genes from less than $1ng/{\mu}L$ of RNA. Repeatability and reproducibility across multiple testing sites resulted in 100% and 98.3% consistencies of risk classification, respectively. Moreover, it was confirmed that the potential interference substances does not affect the risk classification of the test. The findings demonstrate that GenesWell$^{TM}$ BCT have high analytical performance with over 95% consistency for risk classification.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.1
• /
• pp.72-84
• /
• 1993

This study was carried out to understand the varietal variation in physicochemical properties of rice grain and those environmental changes by different transplanting time, and to elucidate the interrelationships among the factors related with eating quality of cooked rice. Fifty three rice samples, among which fifty samples were harvested at ordinary or late transplanted plots of the Crop Experiment Station in Suwon and three samples were harvested orpurchased from Niigata prefecture in Japan, were tested for various physicochemical components of rice grain and some physical factors of cooked rice. All of twenty seven rice cultivars tested were the recent-bred Korean japonica rice showing the wide range of maturity from early to medium-late heading and considerable difference in palatability of cooked rice. Amylose content, taste value by Nireco palatability tester (TVN), iodine blue color of cooking extracts(IB), and the ratio of IB /extracted solid amounts (ES) increased significantly by late transplanting, while viscosity (VN) and Mg / K. N value by Nireco tester, hot-water absorption of milled rice (HA), loss tangent of cooked rice by Rheolograph-Micro(LT), and most viscogram characteristics except setback viscosity (C-P) decreased drastically by late transplanting as compared with ordinary transplanting. Most of physicochemical properties of milled rice revealed narrower varietal variation in lately transplanted plot than in ordinary transplanted one. Protein content (PRO), volume expansion rate of cooked rice(VE), C-P and all physical factors of cooked rice by Rheolograph-Micro showed almost negligible seasonal variation, while amylose content (AM), VN, HA, IB/ES, peak viscosity(P), hot viscosity(H) and breakdown(P-H) viscosity exhibited considerably large seasonal variation. The early-headed varieties revealed lower amylose content and smaller seasonal variation of IB/ES compared with medium or medium-late headed rice varieties. AM was closely associatied with IB and IB / ES and VN was highly correlated with Mg/K. N and TVN in both ordinary and late transplanted plots. VN also was highly negatively correlated with cooking characteristics and highly positively correlated with viscogram properties in ordinary culture. PRO was closely connected with moisture content of milled rice and L T in ordinary transplanted plot. IB, which was closely connected with ES, was also singificantly associated LT, P and P-H in ordinary seasonal culture. IB/ES was highly negatively correlated with P, P-Hand P-H / C-P in ordinary culture but with LT and dynamic viscosity of cooked rice in late seasonal culture. The thirty rice cultivars were largely classified into two varietal groups by cluster analysis with physicochemical properties related with eating quality of cooked rice. Korean and Japanese high-quality rice cultivars were separately distributed in two respective varietal group.

• Journal of Korea Water Resources Association
• /
• v.50 no.7
• /
• pp.455-465
• /
• 2017

Understanding of the two-dimensional velocity field is crucial in terms of analyzing various hydrodynamic and fluvial processes in the riverine environments. Until recently, many numerical models have played major roles of providing such velocity field instead of in-situ flow measurements, because there were limitations in instruments and methodologies suitable for efficiently measuring in the broad range of river reaches. In the last decades, however, the advent of modernized instrumentations started to revolutionize the flow measurements. Among others, acoustic Doppler current profilers (ADCPs) became very promising especially for accurately assessing streamflow discharge, and they are also able to provide the detailed velocity field very efficiently. Thus it became possible to capture the velocity field only with field observations. Since most of ADCPs measurements have been mostly conducted in the cross-sectional lines despite their capabilities, it is still required to apply appropriate interpolation methods to obtain dense velocity field as likely as results from numerical simulations. However, anisotropic nature of the meandering river channel could have brought in the difficulties for applying simple spatial interpolation methods for handling dynamic flow velocity vector, since the flow direction continuously changes over the curvature of the channel shape. Without considering anisotropic characteristics in terms of the meandering, therefore, conventional interpolation methods such as IDW and Kriging possibly lead to erroneous results, when they dealt with velocity vectors in the meandering channel. Based on the consecutive ADCP cross-sectional measurements in the meandering river channel. For this purpose, the geographic coordinate with the measured ADCP velocity was converted from the conventional Cartesian coordinate (x, y) to a curvilinear coordinate (s, n). The results from application of A-VIM showed significant improvement in accuracy as much as 41.5% in RMSE.

• Geophysics and Geophysical Exploration
• /
• v.13 no.3
• /
• pp.268-276
• /
• 2010

Earthquake Hazard Mitigation Law was activated into force on March 2009. By the law, the obligation to monitor the effect of earthquake on the facilities was extended to many organizations such as gas company and local governments. Based on the estimation of National Emergency Management Agency (NEMA), the number of free-surface acceleration stations would be expanded to more than 400. The advent of internet protocol and the more simplified operation have allowed the quick and easy installation of seismic stations. In addition, the dynamic range of seismic instruments has been continuously improved enough to evaluate damage intensity and to alert alarm directly for earthquake hazard mitigation. For direct visualization of damage intensity and area, Real Time Intensity COlor Mapping (RTICOM) is explained in detail. RTICOM would be used to retrieve the essential information for damage evaluation, Peak Ground Acceleration (PGA). Destructive earthquake damage is usually due to surface waves which just follow S wave. The peak amplitude of surface wave would be pre-estimated from the amplitude and frequency content of first arrival P wave. Earthquake Early Warning (EEW) system is conventionally defined to estimate local magnitude from P wave. The status of EEW is reviewed and the application of EEW to Odesan earthquake is exampled with ShakeMap in order to make clear its appearance. In the sense of rapidity, the earthquake announcement of Korea Meteorological Agency (KMA) might be dramatically improved by the adaption of EEW. In order to realize hazard mitigation, EEW should be applied to the local crucial facilities such as nuclear power plants and fragile semi-conduct plant. The distributed EEW is introduced with the application example of Uljin earthquake. Not only Nation-wide but also locally distributed EEW applications, all relevant information is needed to be shared in real time. The plan of extension of Korea Integrated Seismic System (KISS) is briefly explained in order to future cooperation of data sharing and utilization.

• Journal of the Korean earth science society
• /
• v.21 no.1
• /
• pp.59-66
• /
• 2000

In Kyeongsang basin, there were very dynamic magmatic activities, resulting to form volcanic and plutonic rocks. A plutonic recycle appeared in this region. Presumption of the pressure for hornblende-bearing granitic rock among the plutonic rocks, can support important informations for the emplacement depth of Cretaceous Bulgugsa granites in Kyeongsang basin. $Al^T$(Al total) contents of hornblende is related to the pressure, oxygen fugacity, and compositions of other minerals having the solid solution. So we apply the $Al^T$ content of hornblende to several empirical and experimental geobarometer systems to presume the pressure and to determine the emplacement depth of Cretaceous Bulgugsa granites in Kyeongsang basin from the inferred pressure. With the result that we applied the $Al^T$ contents of hornblende to the various geobarometers, there was a positive relationship between the pressure and $Al^T$. The minimum pressure value ranges from 0.73 to 1.70kbar in Kyeongju and the maximum value from 2.02 to 3.16kbar in Kimhae. And then the tectonic setting in Kyeongsang basin has no relation to the emplacement depth of Cretaceous granites and means variations with the movement of vertical component in each area. As we suppose that the density of earth's crust is $2.8g/cm^3$, the average values of the emplacement depth ranges in each area range from 2.6 to 11.4km. These data confirm the previous idea about the emplacement depth of Cretaceous granites in Kyeongsang basin, and these geobarometers using the $Al^T$ contents of hornblende is available though they have much limits. Therefore Cretaceous Bulgugsa granites in Kyeongsang basin was the shallow depth intrusive rut and the exposed granites was the shallow depth crust.

• Investigative Magnetic Resonance Imaging
• /
• v.10 no.2
• /
• pp.98-107
• /
• 2006

Magnetization Transfer (MT) imaging generates contrast dependent on the phenomenon of magnetization exchange between free water proton and restricted proton in macromolecules. In biological materials in knee, MT or cross-relaxation is commonly modeled using two spin pools identified by their different T2 relaxation times. Two models for cross-relaxation emphasize the role of proton chemical exchange between protons of water and exchangeable protons on macromolecules, as well as through dipole-dipole interaction between the water and macromolecule protons. The most essential tool in medical image manipulation is the ability to adjust the contrast and intensity. Thus, it is desirable to adjust the contrast and intensity of an image interactively in the real time. The proton density (PD) and T2-weighted SE MR images allow the depiction of knee structures and can demonstrate defects and gross morphologic changes. The PD- and T2-weighted images also show the cartilage internal pathology due to the more intermediate signal of the knee joint in these sequences. Suppression of fat extends the dynamic range of tissue contrast, removes chemical shift artifacts, and decreases motion-related ghost artifacts. Like fat saturation, phase sensitive methods are also based on the difference in precession frequencies of water and fat. In this study, phase sensitive methods look at the phase difference that is accumulated in time as a result of Larmor frequency differences rather than using this difference directly. Although how MT work was given with clinical evidence that leads to quantitative model for MT in tissues, the mathematical formalism used to describe the MT effect applies to explaining to evaluate knee disorder, such as anterior cruciate ligament (ACL) tear and meniscal tear. Calculation of the effect of the effect of the MT saturation is given in the magnetization transfer ratio (MTR) which is a quantitative measure of the relative decrease in signal intensity due to the MT pulse.