• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.2
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• pp.125-129
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• 2005

Two kinds of physical treatments were examined for the analysis both of intrinsic surface and interior nature of CuInS $e_2$[CIS] and CuGaS $e_2$[CGS] films grown in separated systems. For the first method, a selenium protection layer which was immediately deposited after the growth of the CIS was investigated. The Se cap layer protects CISe surface from oxidation and contamination during the transport under ambient atmosphere. The Se cap was removed by thermal annealing at temperature above 15$0^{\circ}C$. After the decapping treatment at 2$25^{\circ}C$ for 60 min, ultraviolet photoemission and inverse photoemission measurements of the CIS film showed that its valence band maximum(VBM) and conduction band minimum (CBM) are located at 0.58 eV below and 0.52 eV above the Fermi level $E_{F}$, respectively. For the second treatment, an Ar ion beam etching was exploited. The etching with ion kinetic energy $E_{k}$ above 500 eV resulted in broadening of photoemission spectra of core signals and occasional development of metallic feature around $E_{F}$. These degradations were successfully suppressed by decreasing $E_{k}$ below 400 eV. CGS films etched with the beam of $E_{k}$ = 400 eV showed a band gap of 1.7 eV where $E_{F}$ was almost centered.st centered.

• Membrane Journal
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• v.26 no.2
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• pp.116-125
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• 2016

This study described a synthesis of MF having a arsenic removal characteristics and the fundamental research was performed about the simultaneous removal system of both As(III) and As(V) ions with the composite nanofiber membrane (PMF) based on PVdF and MF materials for the water-treatment application. From the TEM analysis, the shape and structure of MF materials was investigated. The mechanical strength, pore-size, contact angle and water-flux analysis for the PMF was performed to investigate the possibility of utilizing as a water treatment membrane. From these results, the PMF11 showed the highest value of mechanical strength ($232.7kgf/cm^2$) and the pore-diameter of composite membrane was reduced by introducing the MF materials. In particular, their pore diameter decreased with an increase of iron oxide composition ratio. The water flux value of PMF was improved about 10 to 60% compared with that of neat PVdF nanofiber membranes. From the arsenic removal characterization of prepared MF materials and PMF, it was shown the simultaneous removal characteristics of both As(III) and (V) ions, and the MF01, in particular, showed the highest adsorption-removal rate of 93% As(III) and 68% As(V), respectively. From these results, prepared MF materials and PMF have shown a great potential to be utilized for the fundamental study to improve the functionality of water treatment membrane.

• Journal of the Korean earth science society
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• v.37 no.7
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• pp.389-397
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• 2016

In order to investigate the light curve difference in visual and infrared wavelength of ${\delta}$ Scuti variable Bo Lyn, observations were performed using BOAO 1.8m reflecting telescope and an infrared detector, KASINICS, with J, H, and Ks filters. Infrared light curves of total 7 nights were obtained between March and April in 2011, and those were compared to the V-filter light curve to examine the differences in period, time of maximum light, amplitude, and shape. From the periodic analysis of infrared light curve, a single frequency of $f_1=10.712cycle/day$, $P=0.09335{\pm}0.00002days$ was obtained, and there was no difference in the period along different wavelengths. In the infrared light curve, a frequency of $2f_1$ was detected. This frequency well explains the asymmetric shape of light curve, one of the characteristics of high-amplitude ${\delta}$ Scuti variables. We compared the locations of the measured infrared maxima and the predicted maxima of V-filter, finding that the times of maxima were delayed about 0.3 phase at infrared wavelengths. Amplitude ratios were adopted to be ${\Delta}J/{\Delta}V=0.328$, ${\Delta}H/{\Delta}V=0.216$, and ${\Delta}Ks/{\Delta}V=0.211$, with the range of variation being smaller at longer wavelengths. It seems that the differences in the times of maxima and amplitude occurred because the changes in brightness of a pulsating variable star are mainly caused by the change in temperature.

• Journal of Korean Society of Forest Science
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• v.96 no.2
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• pp.131-137
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• 2007

The first evidence has been provided about the variation within trnL-trnV and trnF-trnT spacer regions of cpDNAs in Korean fir and Manchurian fir, revealed by PCR-RFLP analysis. Four cpDNA haplotypes have accordingly been recognized by being analyzed using the trnL-trnV/Tru11 primer-enzyme combination and 3 haplotypes using the trnF-trnT/TagI combination, which exhibited inter and intraspecific variation. A total of 6 cpDNA haplotypes were recognized by pooling the PCR-RFLP variants observed in both combinations. Haplotypes 2 and 3 were common for both species investigated, whereas haplotypes 1, 4, and 5 were detected only in Korean fir and haplotype 6 was detected only in Manchurian fir. Although haplotypes 2 and 3 were common in both species, haplotype 2 was major haplotype for Korean fir and haplotype 3 was one of the 2 major haplotypes for Manchurian fir. Restricted occurrence of haplotype 4 in Mt. Halla and haplotype 5 in Mt. Jiri of the Korean fir may represent the existence of geographic isolation by the sea between them. Diagnostic potential of individual haplotypes in discriminating between the two species as well as between their populations is discussed.

• Korean Journal of Plant Taxonomy
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• v.36 no.3
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• pp.163-187
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• 2006

Taxonomic studies were conducted to evaluate the interspecific relationships in Viola albida var. albida and its related taxa using seven populations for morphology, palynology and anatomy. Molecular phylogenetic studies were also examined in 28 populations including 19 Korean, four Chinese, two Japanese, one American population and two outgroups using nrITS, and 27 populations except V pinnata for trnL-F region of chloroplast DNA. Morphological differences was observed among seven populations of three species in leaf shape, but characters such as serrate number of leaf margins, petal size, pistil shape were showed overlap between populations. Pollen shape of seven populations was monad and grain shape on the polar axis was semi-angular. Morphology of aperture was tri-colporate, and the surface sculpturing was scabrate in rugulate. The grain shape of equatorial view of five populations was prolate whereas V albida var. taknhashii type 1 and V albida var. chaerophylloides type 3 were subprolate. The anatomical characters of rnidvein of leaf, petiole, peduncle, root were also described for the species. The stomatal apparatus of the leaves was observed only in abaxial surface, and the number of stoma per unit ($mm^2$) were abundant in incised than lobate or cleft margin of the leaves. The nrITS analysis shows that V. pinnata and V. dissecta was monophyletic and occupied a basal position in the V. albida var. albida and its related taxa. The other clade including infraspecific populations of V. albida, and V. eizanensis was paraphyletic. The trnL-F noncoding region analysis was similar to the ITS tree. According to the above observations in morphology, palynology, anatomy, and molecular phylogenetic analysis, the significant differences were not found except for leaf shape in Viola albida var. albida and its related taxa, therefore V. albida var. takanhashii and V. albida var. chaerophylloides were considered to be an infraspecific taxa of V. albida var. albida rather than an independent species, subvariety or variety of V. pinnata and V. dissecta.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.5
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• pp.555-560
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• 2014

In order to improve spectrum sensitivity of photodiode for detection of the laser wavelength at 850 nm ~ 1000 nm of near-infrared band, this study has produced silicon-based photodiode whose area is $5000{\mu}m{\times}2000{\mu}m$, and the thickness is $280{\mu}m$. It was packed by the TO-5 type. The electrical properties of the dark currents have valued of approximately 0.1 nA for 5 V reverse bias, while the capacitance showed 32.5 pF at frequency range of 1 kHz and about 32.4 pF at the range of 200 kHz for 0 V. In addition, the rising time of output signal was as fast response as 20.92 ns for 10V. For the optical properties, the best spectrum sensitivity was 0.57 A/W for 890 nm, while it was relatively excellent value of 0.37 A/W for 1,000 nm. Over all, there were good spectrum sensitivity for this diode over the range of 870 ~ 920 nm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.9
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• pp.751-757
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• 2000

The r.f. power effect for Pt doping is investigated on structural and electrochemical properties of amorphous vanadium oxide(V$_2$O$_{5}$) film, grown by direct current (d.c.) magnetron sputtering. Room temperature charge-discharge measurements based on a half-cell with a constant current clearly indicated that the Pt doping could improve the cyclibility of V$_2$O$_{5}$ cathode film. Using glancing angle x-ray diffraction(GXRD) and high-resolution transmission electron microscopy (HRTEM) analysis, we found that the Pt doping with 10W r.f. power induces more random amorphous structure than undoped V$_2$O$_{5}$ film. As the r.f. power of Pt target increases. large amount of Pt atoms incorporates into the amorphous V$_2$O$_{5}$ film and makes $\alpha$-PtO$_2$microcrystalline phase in the amorphous V$_2$O$_{5}$ matrix. These results suggest that the semiconducting $\alpha$-PtO$_2$ microcrystalline phase in amorphous matrix lead to a drastically faded cyclibility of 50W Pt doped V$_2$O$_{5}$ cathode film. Possible explanations are given to describe the Pt doping effect on cyclibillity of the amorphous V$_2$O$_{5}$ cathode film battery. film battery.

• Journal of Microbiology
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• v.41 no.1
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• pp.1-6
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• 2003

The genetic relatedness of multidrug-resistant pneumococcal isolates of serotypes 19F and 23F was investigated. The DNA fragments digested with Sma I were resolved by pulsed-field gel electrophoresis (PFGE). PFGE analysis of 365. pneumoniae isolates showed 13 different patterns. Among 22 isolates of serotype 19F, 9 different PFGE patterns were present and 14 isolates of serotype 23F isolates represented 5 distinct PFGE patterns. Two isolates of serotype 19F and six isolates of serotype 23F shared the same PFGE pattern (Pattern I). Based on the genetic relatedness within the strains (one genetic cluster was defined as having more than 85% homology), we divided the pneumococcal strains into genefic clusters (Ⅰ, II, III, IV, V, and VI). The 22 strains of serotype 19F belonged to five distinct genetic clusters (I, II, III, IV, V and VI) and 14 strains of serotype 23F represented two genetic clusters (I and II ). These results showed that strains of serotype 19F are genetically more diverse than those of serotype 23F, Serotype 19F isolates with PFGE patterns H and I appeared to be less related to those of the remaining PFCE patterns (A to G) (less than 60% genetic relatedness), but those strains were genetically closely related with serotype 23f. These results suggest that the latter isolates originated from horizontal transfer of the capsular type 19F gene locus to 23F pneumococcal genotypes. In conclusion, the multidrug-resistant pneumococcal isolates of serotype 19f and 23F isolated in Korea are the result of the spread of a limited number of resistant clones.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.1
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• pp.41-48
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• 2021

Essential thrombocythemia (ET) is a clonal bone marrow stem cell disorder, primarily involving the megakaryocytic lineage. The WHO 2016 guidelines include the molecular detection of JAK2, MPL, and CALR mutations as a major diagnostic criterion for ET. This study aimed to determine the frequency of JAK2 V617F, MPL W515L, and CALR mutations in Iraqi Kurdish patients afflicted with ET, and to analyze their clinical and hematological features. A total of 73 Iraqi Kurdish patients with ET were enrolled as subjects, and analysis was achieved utilizing real-time PCR. The frequency of JAK2 V617F, CALR, and MPL W515L mutations was determined to be 50.7%, 22%, and 16.4%, respectively. No statistically significant difference was obtained when considering the age and gender among different genotypes. The JAK2 V617F mutated patients had significantly higher white blood cell counts and hemoglobin levels than the CALR-positive patients (P-value=0.000, 0.007, respectively), MPL W515L-positive patients (P-value=0.000, 0.000, respectively), and triple negative patients (P-value=0.000, 0.000, respectively). Also, the JAK2 V617F mutated patients showed higher platelet count as compared to the MPL W515L-positive patients (P-value=0.02) and triple negative patients (P-value=0.04). Furthermore, significantly lower white blood cell count and hemoglobin levels were associated with CALR positivity (P-value=0.000, 0.01, respectively), MPL W515L-positivity (P-value=0.001, 0.000, respectively), and triple negativity (P-value=0.000, 0.000, respectively), as compared to patients with combined mutations. In conclusion, apart from a relatively high frequency of MPL W515L mutation, our data is comparable to earlier reports, and highlights the importance of genotyping the JAK2 V617F, MPL W515L, and CALR mutations for accurate diagnosis of patients with ET.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.163-164
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• 2015

LNG복합발전은 수요지 인근에 건설이 가능한 장점이 있어 수도권 인근 발전소 중 상당한 부분을 차지하고 있다. 이러한 LNG 복합발전은 수도권 부하비율 감소에 따라 발전량이 줄어들게 된다. 2018년 계통데이터를 기반으로 수도권의 부하수준이 70%까지 떨어졌을 때, 거의 모든 수도권 복합발전이 정지함을 확인할 수 있다. 이 때, 신가평과 강원을 잇는 765kV급 융통선로의 2회선 상정사고 발생 시 수도권 무효전력 공급원이 줄어들어 전압이 불안정해진다. 이와 같은 상정사고를 대비해 수도권 복합발전 중 일부는 제약운전을 시행해야 한다. 본 논문에서는 제약운전을 하는 수도권 LNG복합발전의 발전량을 대체할 수 있는 대안으로 적절한 위치에 FACTS설비를 투입하고자 한다. FACTS설비를 효율적으로 운전시키기 위해 LNG복합발전의 발전량 감소에 따른 전압변화에 대해 Tangent Vector Component가 가장 큰 수도권 345kV 모선을 선정해 STATCOM을 투입하고 그 결과를 확인한다. 이를 확인하기 위한 방안으로 제약운전을 하는 복합발전의 발전량을 감소시키고 관찰하고자 하는 모선과 거리가 먼 비수도권 발전량을 증가시켜 수급을 맞춘 뒤 전압의 변화를 관찰한다. 이 때, 하나의 계통을 2개의 지역으로 구역화하여 전압을 확인할 수 있는 F-V 해석을 이용한다.