• Journal of the Korean Ceramic Society
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• v.24 no.2
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• pp.117-122
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• 1987

Glass forming ranges in the AlF3-(Mg＋Sr＋Ba)F2-P2O5 system are studied and ultraviolet transmission, infrared transmission, coefficient of refractive index, thermal expansion coefficient, density and chemical durability of the glasses are determined. Glass forming range is restricted MgF2 0-10wt%, SrF2 10-50wt%, BaF2 10-40wt% in this system. While BaF2 is substituted by SrF2, density and refractive index are decreased, micro hardness and thermal expansion coefficient are increased according to the increasing of SrF2 at fixed MgF2 contents. These samples represent high transmittance(93%) from 400nm to 3800nm and chemical durability of these samples show less than 0.3mg/$\textrm{cm}^2$$.$hy by weightloss.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.4
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• pp.244-248
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• 2012

F-Measure is one of the external measures for evaluating the validity of clustering results. Though it has clear advantages over other widely used external measures such as Purity and Entropy, F-Measure has inherently been less sensitive than other validity measures. This insensitivity owes to the definition of F-Measure that counts only most influential portions. In this research, we present $F_n$-Measure, an external cluster evaluation measure based on F-Measure. $F_n$-Measure is so sensitive that it can detect their difference in the cases that F-Measure cannot detect the difference in clustering results. We compare $F_n$-Measure to F-Measure for a few clustering results and show which measure draws better result based upon homogeneity and completeness.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.11
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• pp.1625-1630
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• 2007

A simulation study was conducted to evaluate the effect of reciprocal cross on the detection and characterization of Mendelian QTL in $F_2$ QTL swine populations. Data were simulated under two different mating designs. In the one-way cross design, six $F_0$ grand sires of one breed and 30 $F_0$ grand dams of another breed generated 10 $F_1$ offspring per dam. Sixteen $F_1$ sires and 64 $F_1$ dams were randomly chosen to produce a total of 640 $F_2$ offspring. In the reciprocal design, three $F_0$ grand sires of A breed and 15 $F_0$ grand dams of B breed were mated to generate 10 $F_1$ offspring per dam. Eight $F_1$ sires and 32 $F_1$ dams were randomly chosen to produce 10 $F_2$ offspring per $F_1$ dam, for a total of 320 $F_2$ offspring. Another mating set comprised three $F_0$ grand sires of B breed and 15 $F_0$ grand dams of A breed to produce the same number of $F_1$ and $F_2$ offspring. A chromosome of 100 cM was simulated with large, medium or small QTL with fixed, similar, or different allele frequencies in parental breeds. Tests between Mendelian models allowed QTL to be characterized as fixed (LC QTL), or segregating at similar (HS QTL) or different (CB QTL) frequencies in parental breeds. When alternate breed alleles segregated in parental breeds, a greater proportion of QTL were classified as CB QTL and estimates of QTL effects for the CB QTL were more unbiased and precise in the reciprocal cross than in the one-way cross. This result suggests that reciprocal cross design allows better characterization of Mendelian QTL in terms of allele frequencies in parental breeds.

• Korean Journal of Logic
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• v.20 no.2
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• pp.163-196
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• 2017

Wittgenstein declares in the Tractatus Logico-Philosophicus that he resolved Russell's Paradox. According to him, a function cannot be its own argument. If we assume that a function F(fx) can be its own argument, a proposition "F(F(fx))" will be given, where the outer function F has a meaning different from the inner function F. In consequence, "F(F(fx))" will not be able to have a definite sense. Why, however, does Wittgenstein call into question a function F(fx) and "F(F(fx))"? To answer this question, we must examine closely Russell's own resolution of Russell's Paradox. Only when we can understand Russell's resolution can we do Wittgenstein's resolution. In particular, I will endeavor to show that the idea in Wittgenstein's 1913 letter to Russell provides a decisive clue for this problem.

• Annals of Clinical Neurophysiology
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• v.4 no.2
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• pp.108-113
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• 2002

Background and Objective : Carpal tunnel syndrome (CTS) is the most common mononeuropathy encountered in clinical practice. No single procedure or group of procedures has demonstrated adequate sensitivity. F-wave study in CTS is very rarely reported. To determine the diagnostic usefulness of new parameters of F-wave and comparative study of F-wave parameters of median and ulnar nerves in patients with CTS. Methods : F-wave responses of median and ulnar nerves were analyzed from 27 patients with clinically diagnosed CTS and 22 age and gender-matched normal control. Conventional F-wave parameters were studied. Also, the usefulness of new parameters such as mean and maximal ulnar-median F-wave latency differences, ulnar-median F-wave persistence and chronodispersion differences, median/ulnar F-wave amplitude ratio, and F-wave conduction velocity (FCV) using mean and maximal latency were assessed. Results : Compared with controls, median F-wave minimal, maximal and mean latencies, mean F-wave amplitude/M-wave amplitude, minimal, mean and maximal ulnar-median F-wave latency differences, and FCVs using minimal, maximal and mean latency were significant (P<0.05~0.001). Median F-wave minimal, maximal and mean latencies, mean ulnar-median F-wave latency difference, and FCVs using minimal, maximal and mean latency showed high sensitivity and specificity. Mean ulnar-median F-wave latency difference and FCVs using maximal and mean latency were new parameters. Conclusion : New F-wave parameter including mean ulnar- median F-wave latency difference and FCVs using maximal and mean latency may be a useful to assess the CTS. Also, median F-wave minimal, maximal and mean latencies, and FCV using minimal latency may be included in routine diagnostic tests in CTS.

• The Plant Pathology Journal
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• v.35 no.6
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• pp.543-552
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• 2019

Fusarium asiaticum of the F. graminearum species complex causes head blight in small-grain cereals. The nivalenol (NIV) chemotypes of F. asiaticum is more common than the deoxynivalenol (DON) chemotypes of F. asiaticum or F. graminearum in Korea. To understand the prevalence of F. asiaticum-NIV in Korean cereals, we characterized the biological traits of 80 cereal isolates of F. asiaticum producing NIV or 3-acetyl-deoxynivalenol (3-ADON), and 54 F. graminearum with 3-ADON or 15-acetyl-deoxynivalenol (15-ADON). There was no significant difference in mycelial growth between the chemotypes, but F. asiaticum isolates grew approximately 30% faster than F. graminearum isolates on potato dextrose agar. Sexual and asexual reproduction capacities differed markedly between the two species. Both chemotypes of F. graminearum (3-ADON and 15-ADON) produced significantly higher numbers of perithecia and conidia than F. asiaticum-NIV. The highest level of mycotoxins (sum of trichothecenes and zearalenone) was produced by F. graminearum-3-ADON on rice medium, followed by F. graminearum-15-ADON, F. asiaticum-3-ADON, and F. asiaticum-NIV. Zearalenone levels were correlated with DON levels in some chemotypes, but not with NIV levels. Disease assessment on barley, maize, rice, and wheat revealed that both F. asiaticum and F. graminearum isolates were virulent toward all crops tested. However, there is a tendency that virulence levels of F. asiaticum-NIV isolates on rice were higher than those of F. graminearum isolates. Taken together, the phenotypic traits found among the Korean F. asiaticum-NIV isolates suggest an association with their host adaptation to certain environments in Korea.

• The Journal of Korean Physical Therapy
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• v.12 no.2
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• pp.29-37
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• 2000

본 연구의 목적은 힘판(Force plate)의 지면반발력(Ground reaction force)의 비교에 따라 발압력 측정계(F-메트와 F-스킨)의 상호 기계간의 신뢰성과 타당성을 연구하는 데에 목적을 두고 있으며 정상인과 리스프랑크(Lisfranc) 골절을 가지고 있는 환자를 대상으로 분석 연구하게 되었다. 힘판의 지면 반발력을 기준치로 설정하고 정상인과 환자의 각각 오른발과 왼발의 스텝에 대해 F 메트(F-mat) 와 F 스캔(F-scan) 시스템의 그래픽 비교 모식과 시간에따른 보령분석의 차이에 따라 이 논문에 대한 결과를 얻을 수 있었다. 본 연구에서는 F 스킨 시스템의 데이터 분석기인 새로운 버전 3.622와 마이크로 소프트웨어인 엑셀 97을 통해 새 시스템의 힘의 평균치와 그래픽을 통해 비교 분석하게 되었으며 다음과 같은 세가지 결론을 얻을 수 있었다. 첫 번째로 F스캔의 지면 반발력은 힘판과 비교되어질 때 통계학적으로 중요한 차이점을 얻을 수 없을 것이다. 두 번째, F 메트를 위한 지면 반발력 역시 힘판과 비교되어질 때 통계학적으로 중요한 차이점율 얻음 수 없을 것이다. 세 번째로 정상군과 실험군의 지면 반발력에 대해 중요한 차이점이 있을 것이라는 것이 밝혀졌다. 특히 정상군의 대상자는 실험군의 대상자와 비교되어질 때 각 발에 대해 증가된 지면 반발력을 나타내었다. 이상 본 연구에 대해 다음의 결론을 내릴 수가 있었고 기존의 F 스캔 시스템이 임상적으로 많이 쓰여졌지만 F 스캔의 센서에 대해 많은 이견 차이를 보였었다. 한편. F메트 시스템에서 F메트 센서의 일관성에 대해서는 어느 연구 논문도 나오지 않았고 이에 대해 F스캔(F-scan)과 힘판(Force plate)를 상호 비교하여 F메트 시스템에 대한 신뢰성과 타당성을 연구하는데 목적을 두게되었다.

• The Journal of the Acoustical Society of Korea
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• v.34 no.4
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• pp.288-294
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• 2015

The fiber optic Sagnac interferometer is well established as a sensor for detection of physical perturbations such as acoustic and vibration. In this paper acoustic signals generated in the cylindrical cavity submerged in transformer oil were measured by the fiber optic sensor array in one Sagnac loop. Two different external sound frequencies, $f_1$ and $f_2$, were applied to the sensor array simultaneously by using piezoelectric with frequency range from 5 kHz to 90 kHz. Based on the experimental results, fiber optic sensor detected harmonic series of applied sound frequency such as $f_1$, $f_2$, $2f_1$, $2f_2$, ${\mid}f_1-f_2{\mid}$, ${\mid}f_1+f_2{\mid}$. Suggested fiber optic sensor array can be applied to monitor physical quantities such as internal sound pressure and vibration due to partial discharge in the real electric transformer system.

• 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.

• Journal of the Korean Magnetics Society
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• v.16 no.5
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• pp.261-263
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• 2006

In order to investigate the magnetic properties of Eu ions in the single crystal $MnF_2$, the temperature dependent magnetic susceptibilities of the antiferromagnetic $MnF_2$ and the single crystal $MnF_2$(1.5% $EuF_3$) with the rutile structures were measured in the temperature range from 4K to 300K. The detailed analysis of the measured susceptibilities showed that the magnetic susceptibility by the doping of the small amount $EuF_3$ in the antiferromagnetic single crystal $MnF_2$ follows the antiferromagnetic Curie-Weiss law with the negative paramagnetic Curie temperature similarly as in $MnF_2$. It was also found that Eu ion has +3 valence. This solves the long standing discrepancy on this problem.