• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.6
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• pp.89-96
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• 2019

This study was carried out for management of the invasive alien plants in Mt. Inwang located in central Seoul. The invasive alien plants are 11 families, 34 genera, 30 taxa, and they are 10.8% of the total vascular plants(314 taxa). The ecosystem disturbed plants designated by the Korea environment ministry are 6 taxa : Rumex acetosella, Lactuca scariola, Ambrosia trifida var. trifida, Ambrosia artemisiifolia, Aster pilosus and Eupatorium rugosum. In the life-form, herbaceous perennials are 13 taxa(35.3%). In the continent of origin, the species from America are 20 taxa(58.8%). In the introduction time, the species of third period are 14 taxa(41.2%). In the diffusion grade, 5 grade species are 14 taxa(41.2%) and they are wide spread species. Mt. Inwang was designated as ecological scenery conservation area of Seoul in 2007. But Mt. Inwang is in high danger by the spread of invasive alien plants and ecosystem disturbed plants, due to artificial factors such as development pressure and the occurrence of byway trail. Therefore, Mt. Inwang needs systematic management of invasive alien plants and monitoring of long-term changes.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.3
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• pp.757-766
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• 2017

This study investigated not only the existence of differently functioned item due to gender but also domain. In this study, the randomly selected data of TIMSS 2007, which consist of 681 male and 646 women, were analyzed. To detect differently functioned items, this study employed Raju method. For Raju method, three-parameter logistic model was selected. Signed and unsigned area between two item characteristic curve were measured within the real ability range. An item which was detected commonly SA and UA area in Raju method was defined as a differently functioned item. As a result of this study, six items among twenty seven items of mathematics in the TIMSS 2007 were differently functioned item. Five items among those six items, were in favor of boys and one item was in favor of girls. Number, Geometric Shapes and Measures, and Applying were in favor of boys. but Data Display, Reasoning were in favor of girls. The conclusion of this study was summarized as existing differently functioned items in TIMSS 2007 and difference between favorable domain based gender. Finally, it is desirable to consider the differently functioned items by relating those item content for improving the test reliability of TIMSS 2007.

• Computers and Concrete
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• v.14 no.6
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• pp.675-694
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• 2014

Annular and solid concrete specimens with different aspect ratios and static unconfined compressive strengths were studied for impact loading using SHPB test setup. Numerical simulations in LSDYNA were also carried out and results were validated. The stress-strain curves obtained under dynamic loading were also compared with static compressive tests. The mode of failure of concrete specimen was a typical ductile failure at high strain rates. In general, the dynamic increase factor (DIF) of thin solid specimens was higher than thick samples. In the numerical study, the variation of axial, hydrostatic and radial stresses for solid and annular samples was studied. The core phenomenon due to confinement was observed for solid samples wherein the applied loads were primarily borne by the innermost concrete zone rather than the outer peripheral zone. In the annular samples, especially with large diameter inside hole, the distribution of stresses was relatively uniform along the radial distance. Qualitatively, only a small change in the distribution of stresses for annular samples with different internal diameters studied was observed.

• Korean Journal of Clinical Pharmacy
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• v.22 no.1
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• pp.73-80
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• 2012

This study was to determine the inappropriate drug use in pediatric outpatients who received 2 or more prescriptions on the same day. Retrospective drug utilization reviews (DURs) were implemented to samples obtained from national health insurance claims data during December 2008 to February 2009, using 5 DUR criteria (duplication, drug-drug interaction, drug-disease interaction, drug-age contraindication, incorrect dosage) established in the Drug Information Framework (DIF)-$Korea^{TM}$, DUR program. Among 38,451 claims analyzed in the study, 74.7% had more than one conflicts in the 5 DUR modules. Among 16,472 patients analyzed, 49.6% had conflicts with duplication criteria composing of ingredient duplication (23.3%) and therapeutic class duplication (39.6%). Incorrect dosages were found in 73.6% of patients and under-dosage conflicts accounted for 59.9%, which was higher than over-dosage conflicts (38.3%). In this study, inappropriate drug prescriptions such as under-dose, pediatric contraindication and therapeutic duplication were prevalent in pediatric outpatient settings, suggesting much more awareness to the society, to prevent drug related problems in a vulnerable pediatric group.

• Journal of Biomedical Engineering Research
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• v.14 no.1
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• pp.23-30
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• 1993

We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs and others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized nomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh loci computer. The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal (tare Index are greater by the amount of approximately 8" and 0.5, respectively, (2) the shape of the isthmus cross section is more round , and (3) the distance between the lesser trochanter and the proximal border of the isthmus is shorter by about 15 mm. The results suggested that the femoral component suitable for Asians should be dif- ferent (rom the currently-used components designed and manufactured mostly by European or American companies.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.6
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• pp.550-557
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• 2001

There are several applications and error analysis methods using GPS(Global Positioning System) In most analysis positioning and timing errors are represented as the multiplication of DOP(Dilution Of Precision) and measurement errors, which are affected by the receiver and measurement type. Therefore, lots of DOPs are defined and used to analyze and predict the performance of positioning and timing systems. In this paper, the relationships between these DOPs are investigated in detail, The relationships between GDOP(Geometric DOP), PDOP(Position DOP) and TDOP(Time DOP) in the absolute positioning are de-rived. Using these relationships, the affect of clock bias is analyzed. The relationships between RGDOP(Relative DOP) and PDOP are also derived in relative positioning where the single difference and double dif-ference techniques are used. From the results, it is expected that using the common clock will give better performance when the single difference technique is used while the effects of clock is eliminate when the double difference technique is used. Finally, the error analyses of dual frequency receivers show that the narrow lane measurements give more accurate results than wide line of or L1. L2 independent measurements.

• Parasites, Hosts and Diseases
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• v.22 no.2
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• pp.253-258
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• 1984

Experimentally, primary amoebic meningoencephalitis (PAM) is induced by Naegleria fowleri in mouse and development of PAM may be inauenced by the strain, weight and sex of mouse, and inoculum size of N. fowleri trophozoite. In this paper, the effect of these factors on PAM development of mouse was studied. N. fowleri trophozoites, strain 0359, were introduced into mouse intranasally under secobarbital anesthesia (0.05mg/g). 1. PAM was developed more frequently in BALB/C mouse than ICR mouse. 2. The survival time of mouse with PAM was influenced by the weight, that is, it was shorter in 15 g mouse than in the heavier groups. 3. No difEerence was observed on PAM development according to sect. 4. In case of inoculated amoeba, PAM incidence of $0.5{\times}10^4$ was markedly decreased.

• Journal of the Korean Ceramic Society
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• v.35 no.2
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• pp.123-128
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• 1998

Multilayer ceramic capacitors(MLCC) were prepared by laminating the layer of composition with dif-ferent Curie temperature to improve temperature coefficient in the Pb(Mg1/3Nb2/3)O3-PbTiO3 binary system. Green sheet was formed by tape casting using Pb(Mg1/3Nb2/3)O3-PbTiO3 and PbTiO3 synthesized with solid state reaction of PBO. Nb2O5 MgO and TiO2. Green sheet with electrode of 70Ag-30Pd was laminated under 300 kg/cm2 at 70$^{\circ}C$ and sintered at 1100$^{\circ}C$ for 2hr. Curie temperatues for MLCC with 10 layers of pure PMN and 0.9PMN-0.1PT were lowered to -22$^{\circ}C$ and 36$^{\circ}C$ respectively. MLCC with 7 layers of PMN and 3 layers of 0.9PMN-0.1PT showed nearly zero temperature coefficient of capacitance in the range of -20∼30$^{\circ}C$ and sum of dissipation factor of each layer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.5
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• pp.410-414
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• 2013

Rapid thermal processing (RTP) abruptly decreases the time required to perform solar cell processes. RTP were used to form emitter of crystalline silicon solar cells. The emitter sheet resistance is studied as a function of time and temperature. The objective of this study is reduction of doping process time with same performance. Emitter difRapid thermal dfusion was carried out by using a spin on doping and a RTP. iffusion was performed in the temperature range of $700{\sim}750^{\circ}C$ for 1m 30s~15 m. Thermal budgets yielded a $50{\Omega}/sq$ emitter using a P509 source. To reduce process time and get high efficiency, rapid thermal diffusion by IR lamp was employed in air atmosphere at $700^{\circ}C$ for 15 m.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.675-678
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• 2008

The effect of wave and current interactions on jet-like current flowing against waves was investigated based on numerical simulations. The numerical simulations are conducted by a combined model system of REF/DIF(a wave model) plus SHORECIRC(a current model) and a Boussinesq equation model, FUNWAVE. In the simulations, regular and irregular waves refracted due to the jet-like opposing current were focused along the core region of current, and the jet-like current was earlier spreaded when the waves had larger wave heights. The numerical results show that the rapid change of wave height distribution in transverse direction near current inlet plays a significant role to spread the jet-like current. In other words, the gradients of radiation stress forcing in transverse direction have a more significant effect on the jet-like current than its relatively small gradients forcing in flowing direction, which tend to accelerate the current, do. In conclusion, it is indispensible to take into account the interaction effect of wave transformation and current characteristics when waves meet the opposing jet-like current such as river mouth.