• Journal of electromagnetic engineering and science
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• v.13 no.1
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• pp.38-43
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• 2013

We derive the Z-parameters for the two coupled antennas used for wireless power transfer under the assumption that the antennas are canonical minimum scattering antennas. Using the Z-parameter and the maximum power transfer efficiency formula, we determine the maximum power transfer efficiency of wireless power transfer systems. The results showed that the maximum power transfer efficiency increases as the mode number or the radiation efficiency increases. To verify the theory, we fabricate and measure two different power transfer systems: one comprises two antennas generating $TM_{01}$ mode; the other comprises two antennas generating $TM_{02}$ mode. When the distance between the centers of the antennas was 30 cm, the maximum power transfer efficiency of the antennas generating the $TM_{02}$ mode increased by 62 % compared to that of the antennas generating the $TM_{01}$ mode.

• Korean Journal of Optics and Photonics
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• v.15 no.4
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• pp.321-324
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• 2004

We have composed an experimental system using the superposition method to measure the nonlinearity of photodetectors for optical fiber power measurements. Also we have measured the nonlinearity of a high power detector and of a low power detector. The two detectors have shown good linearity within 0.01% and 0.02%, respectively, in the 50 ㏈ dynamic range. These detectors are used as reference detectors in optical fiber characteristics measurements.

• Journal of The Korean Astronomical Society
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• v.26 no.2
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• pp.99-101
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• 1993

We have searched for the 2 mm transitions of $H_2COH^+(2_{02}-1_{01})$ and $H_2\;^{13}CO(2_{02} - 1_{01},\; 2_{12}-1_{11},\;and\;2_{11}-1_{10})$ toward the dense interstellar molecular clouds Orion A, TMC-1 and L134N using the FCRAO 14 m telescope. None of the transitions have been detected except the $H_2\;^{13}CO$ transitions toward Orion-KL. We set upper limits for the abundances of the protonated formaldehyde ion $(H_2COH^+)$, which are close to the abundances expected from ion-molecule chemistry.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.2
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• pp.107-120
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• 2021

The Komdok Pb-Zn deposit, which is the largest Pb-Zn deposit in Korea, is located at the Hyesan-Riwon metallogenic zone in Jiao Liao Ji belt included Paleoproterozoic Macheolryeong group. The geology of this deposit consists of Paleoproterozoic metasedimentary rocks, Jurassic Mantapsan intrusive rocks and Cenozoic basalt. The Komdok deposit which is a SEDEX type deposit occurs as layer ore and vein ore in the Paleoproterozoic metasedimentary rocks. Based on mineral petrography and paragenesis, dolomites from this deposit are classified four types (1. dolomite (D₀) as hostrock, 2. early dolomite (D₁) associated with tremolite, actinolite, diopside, sphalerite and galena from amphibolite facies, 3. late dolomite (D₂) associated with talc, calcite, quartz, sphalerite and galena from amphibolite facies, 4. dolomite (D₃) associated with white mica, chlorite, sphalerite and galena from quartz vein). The structural formulars of dolomites are determined to be Ca_1.00-1.20Mg_0.80-0.99Fe_0.00-0.01Zn_0.00-0.02(CO₃)₂(D₀), Ca_1.00-1.02M_0.97-0.99Fe_0.00-0.01Zn_0.00-0.02(CO₃)₂(D₁), Ca_0.99-1.03Mg_0.93-0.98Fe_0.01-0.05Mn_0.00-0.01As_0.00-0.01(CO₃)₂(D₂) and Ca_0.95-1.04Mg_0.59-0.68Fe_0.30-0.36Mn_0.00-0.01 (CO₃)₂(D₃), respectively. It means that dolomites from Komdok deposit have higher content of trace elements (FeO, MnO, HfO₂, ZnO, PbO, Sb₂O₅ and As₂O₅) compared to the theoretical composition of dolomite. These trace elements (FeO, MnO, ZnO, Sb₂O₅ and As₂O₅) show increase and decrease trend according to paragenetic sequence, but HfO₂ and PbO elements no show increase and decrease trend according to paragenetic sequence. Dolomites correspond to Ferroan dolomite (D₀, D₁ and D₂), and Ferroan dolomite and ankerite (D₃), respectively. Therefore, 1) dolomite (D₀) as hostrock was formed by subsequent diagenesis after sedimentation of Paleoproterozoic (2012~1700 Ma) silica-bearing dolomite in the marine evaporative environment. 2) Early dolomite (D₁) was formed by hydrothermal metasomatism origined metamorphism (amphibolite facies) associated with intrusion (1890~1680 Ma) of Paleoproterozoic Riwon complex. 3) Late dolomte (D₂) was formed from residual fluid by a decrease of temperature and pressure. and dolomite (D₃) in quartz vein was formed by intrusion (213~181 Ma) of Jurassic Mantapsan intrusive rocks.

• Journal of dental hygiene science
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• v.12 no.4
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• pp.310-319
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• 2012

In this study, 1,495 cases of computerized data collected as disease entities of oral and maxillofacial injuries among patient visiting S university hospital located in Seoul in 2009 were analyzed and following results were obtained. It was found that the injury incidence in male was greater than in female (1.49:1), it occurred most frequently in the age of 7~14 years old (19.6%), and its most frequent cause was falling down (25.9%). Injuries occurred in other place including beach and open-air (24.7%) most frequently, often developed in anterior teeth (43.2%) and posterior teeth (43.1%), their incidence was relatively higher between 15:00~17:00 (10.4%) and 19:00~23:00 (7.1%) O'clock. In the relationship between causes of the injury and the diagnosis based on the international classification of disease), falling, fall, impingement, violence, traffic accident, sports and own making accident caused most frequently lip and oral open injuries (S01.5), open fracture of tooth (S02.51), close fracture of tooth (S02.50), close fracture of mandible (S02.60), close fracture of tooth (S02.50), respectively. From the above results, it is necessary to understand general characteristics of oral and maxillofacial injuries and to consider their trends for the establishment of systematic complement policies and for the performing safety training and public relations activities.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.67-71
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• 2013

Purpose: The Change of CT exposure condition have a effect on image quality and patient exposure dose. In this study, we evaluated effect CT image quality and SUV when CT parameters (Pitch, Rotation time) were changed. Materials and Methods: Discovery Ste (GE, USA) was used as a PET/CT scanner. Using GE QA Phantom and AAPM CT Performance Phantom for evaluate Noise of CT image. Images are acquired by using 24 combinations that four stages pitch (0.562, 0.938, 1.375, 1.75:1) and six stages X-ray tube rotation time (0.5s-1.0s). PET images are acquired using 1994 NEMA PET Phantom ($^{18}F-FDG$ 5.3 kBq/mL, 2.5 min/frame). For noise test, noise are evaluated by standard deviation of each image's CT numbers. And then we used expectation noise according to change of DLP (Dose Length Product) to experimental noise ratio for index of effectiveness. For spatial resolution test, we confirmed that it is possible to identify to 1.0 mm size of the holes at the AAPM CT Performance Phantom. Finally we evaluated each 24 image's SUV. Results: Noise efficiency were 1.00, 1.03, 1.01, 0.96 and 1.00, 1.04, 1.02, 0.97 when pitch changes at the QA Phantom and AAPM Phantom. In case of X-ray tube rotation time changes, 0.99, 1.02, 1.00, 1.00, 0.99, 0.99 and 1.01, 1.01, 0.99, 1.01, 1.01, 1.01 at the QA Phantom and AAPM Phantom. We could identify 1.0 mm size of the holes all 24 images. Also, there were no significant change of SUV and all image's average SUV were 1.1. Conclusion: 1.75:1 pitch is the most effective value at the CT image evaluation according to pitch change and It doesn't affect to the spatial resolution and SUV. However, the change of rotation time doesn't affect anything. So, we recommend to use the effective pitch like 1.75:1 and adequate X-ray tube rotation time according to patient size.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.787-796
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• 2003

Two experiments were conducted to investigate the effect of germanium biotite (GB) on growth performance, nutrient digestibility and fecal gas emission in pigs. In Exp 1., a total of one hundred nursery pigs (initial body weight 13.12${\pm}$0.15kg) were used in a 21 d growth assay. The five treatments were control (CON, basal diet), GB0.5-200 (basal diet + 0.5% GB, 200mesh), GB1.0-200 (basal diet + 1.0% GB, 200mesh), GB0.5-325 (basal diet + 0.5% GB, 325mesh), GB1.0-325 (basal diet + 1.0% GB, 325mesh). Each treatment had four replicates with five pigs per replicate. ADG, ADFI and gain/feed were not significantly different among the treatments. Fecal NH3-N concentration of pigs fed the GB325 diet was lower than that of pigs fed the GB200 diet (P=0.01). The GB treatments reduced fecal volatile fatty acids significantly compared to the CON (propionic acid, P=0.01; butyric acid, P=0.01; acetic acid, P=0.02). Especially, fecal propionic acid concentration of pigs fed the GB325 diets was lower than that of pigs fed the GB200 diets (P=0.02). In Exp 2., a total of seventy five pigs (initial body weight 21.18${\pm}$0.15kg) were used in a 28 d growth assay. The treatments were same as described for Exp. 1. Each treatment had five replicates with three pigs per replicate. The GB1.0 treatments significantly increased the ADG compared to the GB0.5 treatments (P=0.03). The DM and N digestibility of pigs fed the GB1.0 diets were higher than that for pigs fed the GB0.5 diets (P=0.01). Also, the Ca digestibility of pigs fed the GB diets was higher than that for pigs fed the CON diets (P=0.01). The fecal NH3-N concentrations for the GB treatments were lower than that for the CON (P=0.01). The GB325 treatments significantly decreased the fecal NH3-N concentration compared to the GB200 treatments (P=0.03). The fecal butyric acid concentration for the GB325 treatments was lower than that for the GB200 treatment (P=0.04). In conclusion, the results obtained from these feeding trials suggest that the dietary GB for nursery pigs affects fecal noxious gas emission. In growing pigs, dietary GB was effective to improve ADG and decrease fecal noxious gas emission.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.383-391
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• 2007

This study was conducted for an assessment through the estimation of soil loss by each catchment classified by soil catena. Ten catchments, which are Geumgang21, Namgang03, Dongjincheon, Gapyongcheon01, Gyongancheon02, Geumgang16, Byongsungcheon01, Daesincheon, Bukcheon02, Youngsangang08, were selected from the hydrologic unit map and the detailed soil digital map (1:25,000) for this study. The catchments like Geumgang21, Namgang03, Dongjincheon, Gapyongcheon01 and Gyongancheon02 were mainly composed with soils originated from gneiss. The catchments like Geumgang16, Byongsungcheon01, Daesincheon, Bukcheon02 and Youngsangang08 were mainly composed with soils originated from granites. The grades, which are divided into seven grades with A(very tolerable), B(tolerable), C(moderate), D(low), E(high), F(severe), G(very severe), of soil erosion estimated by USLE in catchments were distributed in most A and B because of paddy land and forestry. In detailed, the soil erosion grade of catchments mainly distributing soils originated from gneiss showed more the distribution of B and C than it of catchments mainly distributing soils originated from granites. The reason of results would be derived from topographic characteristics of soils originated from gneiss located at mountainous. The soil loss according to soil catena linked with Songsan and Jigok series, which are soils originated from gneiss was calculated with $7.66ton\;ha^{-1}\;yr^{-1}$. The soil loss of Geumgang16, Byongsungcheon01, Daesincheon, Bukcheon02 which have the soil catena linked with Samgak and Sangju soil series originated from granite, was calculated with $5.55ton\;ha^{-1}\;yr^{-1}$. The soil loss of Youngsangang08 which have the soil catena linked with Songjung and Baeksan soil series originated from granite was calculated with $9.6ton\;ha^{-1}\;yr^{-1}$, but the conclusion on soil loss in this kind of soil catena would be drawn from the analysis of more catchments. In conclusion, the results of this study inform that the classification of soil catena by catchments and estimation of soil loss according to soil catena would be effective for analysis on the grade of non-point pollution by soil erosion in a catchment.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.3
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• pp.281-290
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• 2004

The main purpose of this study was to characterize the air pollutants emission factors in electric power plant (EPP) using fossil fuels. The electric power plant is a major air pollution source, thus knowing the emission characteristics of electric power plant is very important to develop a control strategy. The major air pollutants of concern from EPP slacks are particulate matter (PM), sulfur oxides (SOx), nitrogen oxides (NOx), carbon monoxide (CO) and heavy metals. Throughout the study, the following results are estimated - PM : 8.671E-05 ∼ 8.724E+01 PM emission (kg) per fuel burned (ton) - SOx : 4.149E-04∼7.877E+01 SOx emission (kg) per fuel burned (ton) - NOx 1.578E-02∼9.857E+00 NOx emission (kg) per fuel burned (ton) - CO : 3.800E-04∼1.291E+00 CO emission (kg) per fuel burned (ton) - Hg : 1.220E+01∼3.108E+02 Hg emission (mg) per fuel burned(ton) From the statistical analysis by Wilcoxon signed ranks test between the emission factors of ours and U.S. EPA's, we can yielded that : p 〉0.05.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.1
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• pp.9-16
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• 2016