• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.1
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• pp.93-113
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• 2020

According to information theory, non-orthogonal transmission can achieve the multiple-user channel capacity with an onion-peeling like successive interference cancellation (SIC) based detection followed by a capacity approaching channel code. However, in multiple antenna system, due to the unideal characteristic of the SIC detector, the residual interference propagated to the next detection stage will significantly degrade the detection performance of spatial data layers. To overcome this problem, we proposed a modified power-domain non-orthogonal multiple access (P-NOMA) scheme joint designed with space-time coding for multiple input multiple output (MIMO) NOMA system. First, with proper power allocation for each user, inter-user signals can be separated from each other for NOMA detection. Second, a well-designed quasi-orthogonal space-time block code (QO-STBC) was employed to facilitate the SIC-based MIMO detection of spatial data layers within each user. Last, we proposed an optimization algorithm to assign channel coding rates to balance the bit error rate (BER) performance of those spatial data layers for each user. Link-level performance simulation results demonstrate that the proposed time-space-power domain joint transmission scheme performs better than the traditional P-NOMA scheme. Furthermore, the proposed algorithm is of low complexity and easy to implement.

• Bulletin of the Korean Mathematical Society
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• v.54 no.4
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• pp.1323-1330
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• 2017

For a nondegenerate projective irreducible variety $X{\subset}{\mathbb{P}}^r$, it is a natural problem to find an upper bound for the value of $${\ell}_{\beta}(X)=max\{length(X{\cap}L){\mid}L={\mathbb{P}}^{\beta}{\subset}{\mathbb{P}}^r,\;{\dim}(X{\cap}L)=0\}$$ for each $1{\leq}{\beta}{\leq}e$. When X is locally Cohen-Macaulay, A. Noma in [10] proves that ${\ell}_{\beta}(X)$ is at most $d-e+{\beta}$ where d and e are respectively the degree and the codimension of X. In this paper, we construct some surfaces $S{\subset}{\mathbb{P}}^5$ of degree $d{\in}\{7,{\ldots},12\}$ which satisfies the inequality $${\ell}_2(S){\geq}d-3+{\lfloor}{\frac{d}{2}}{\rfloor}$$. This shows that Noma's bound is no more valid for locally non-Cohen-Macaulay varieties.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.834-838
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• 1996

The diagnosis of the plasma in the facing targets sputtering system was performed in mixture gas of Ar 0.18-0.0 Pa, Xe 0.0-0.18 Pa and $O_2$ 0.02 Pa by using Langmiur's probe and the effect of plasma-damage to surface smoothness and magnetic characteristics of Ba ferrite films was clarified. The electron density $N_e$ and the electron temperature $T_e$ were evaluated at the center of the plasma and at the neighborhood of the anode ring. $T_e$ decreased and $N_e$ increased with increase of $P_{Xe}$ at the center of plasma. For the measurement at the neighborhood of the anode ring, $T_e$ was almost constant and $N_e$ took the minimum value at $P_{Xe}$ of 0.1 Pa, where Ba ferrite films with excellent c-axis orientation and magnetic characteristics were obtained. It was suggested that the restriction of the bombardment of recoiled particles as well as the suppress of plasma-damage were effective for obtaining good surface smoothness and excellent magnetic characteristics and it was useful for decreasing the crystallization temperature of Ba ferrite films.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.2
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• pp.195-202
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• 2018

The purpose of this study is to analyze the cariogenicity of vitamin supplements for children by the Caries Potentiality Index (CPI), pH drop capacity, proliferation rate of Streptococcus mutans. Four vitamin supplements were selected - Noma (NM), Cenovis Kids (CK), Animal Parade (AP), and Character Vitamin (CV). CPI value decreased in the order of AP, CV, CK, and NM. Initial values of all experimental groups showed acidity below pH 7.0. Analysis of the colony forming units of Streptococcus mutans showed that NM and CV resulted a higher proliferation rate (p < 0.05) than CK and AP (p < 0.05). Bacterial activity of the control group was lower than other groups when observed with a confocal laser scanning microscope. Considering the bacterial activity and acidity of vitamin supplements, it is necessary to pay close attention when children taken the vitamin supplements for their oral health.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.450-459
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• 2007

This study was performed to assess the relationships between bone mineral density(BMD), anthropometric measurements, and maternal factors in postmenopausal women. The anthropometric measurements were taken by a trained practitioner, and the maternal factors of the 85 subjects in Chungnam were acquired by an interview questionaire. The BMDs of the lumbar $spines(L_2-L_4)$, femoral necks(FN), ward's triangles(WT), and trochanters(TR) were measured by dual energy X-ray absorptiometry(DEXA). The BMDs(T-score) for $L_2-L_4$, FN, and WT were 0.996 $g/cm^2$(-1.601), 0.697 $g/cm^2(-1.657)$, and 0.793 $g/cm^2(-1.512)$ respectively, which were assessed as osteopenia by the T-score ; TR was noma1 at 0.718 $g/cm^2(-0.675)$. The 85 subjects in Chungnam were divided into three groups according to their BMD measurements for $L_2-L_4$ and FN, assessed by the T-score. The percentages in the osteoporosis, osteopenia, and normal groups were 32.9%, 42.4, and 24.7%, respectively. The average age was significantly the highest in the osteoporosis group than in the other two osteopenia and normal group(p<0.001). The subjects' BMDs were positively correlated with weight, height, BMI, waist, WHR, OBR and hip circumference, and negatively correlated with the age, duration time after menopause, lactation, the age of last delivery, menarche age, and number of children. The average age at menopause was 48.8. The osteoporosis group's average age at menopause was lower than those of the other groups. However, the BMD of the lumbar spine positively correlated with duration time after menopause and the BMD of the femoral neck with lactation, last delivery, menarch age, number of children. Therefore, researches are needed to find out the effective way to minimize the effect of age and other physiological conditions on the decrease of bone mass density.

• Microbiology and Biotechnology Letters
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• v.29 no.3
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• pp.181-185
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• 2001

The naturally occurring chemical indole-3-carbinol (13C), found in vegetables of the Brassica genus, is a promising anticancer agent that was shown previ- ously to induce a Gl cell cycle arrest of human breast cancer cell lines, independent of estrogen receptor signaling. The anticancer activity of 13C and the possible mechanisms of its action were explored in a human hepatocellular carcinoma cell line, HepG2. Treatment of HepG2 cells with 13C suppressed the growth of the cells. The growth sup- pression caused by 13C ($IC_{50}$/: 444$\mu$M) was found to be partially due to its ability to stop the cell cycle in HepG2 cells. Western blot analysis for the Gl phase artiest demonstrated that the expression-levels of cyclin-dependent kinase (Cdk4, Cdk6) and cyclic D were reduced strongly after treatment of Hep72 cells with 13C (4007M) for 24- 72 hrs. Furthermore, I3C selectively abolished the expression of Cdk6 in a dose- and time-dependent manner, and accordingly, inhibited the phosphorylation of retinoblastoma. Interestingly, after the HepG2 cells reached their max- imal growth arrest, the level of the p21, a well-known Cdk inhibitor, increased significantly. Therefore, it could be considered that the Gl arrest of HepG2 cells treated with 13C was due to the indirect inhibition of Cdk4/6 activities by p21 Western blot analysis for G2/M phase arrest of demonstrated the levels of Cdc2 and cyclin Bl werer reduced dramatically after the treatment of HepG2 cells with 13C ($40\mu$M) for 24-72 hrs. flow cytometry of propidium iodide-stained HepG2 cells revealed that 13C induces a Gl (53%,72hr incubation) and G2 (25%,24hr incubation) cell cycle arrest. Thus, our observations have uncovered a previously undefined antiproliferative pathway for r3C that implicates Cdk4/6 and Cdc2 as a target for cell cycle control in human HepG2 cells. However, the 13C-medi- ated cell cycle arrest and repression of Cdk4/6 production did not affect the apoptotic induction of HepG2 cell.

• Tuberculosis and Respiratory Diseases
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• v.46 no.4
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• pp.542-547
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• 1999

Background: Decision in mediastinal lymph node involvement of lung cancer by CT scan is very important and valuable for the treatment planning and prognosis prediction. In general, long diameter of mediastinal lymph node more than 15mm is used as criterion of lung cancer involvement. Adenocarci-noma has a tendency of early distant metastasis and micrometastasis, so adenocarcinoma may involve lymph node earlier and cannot be detected before lymph nodes are enlarged enough. The authors tried to determine the difference between two size criteria(15mm, 10mm) in adenocarcinoma for the detection of cancer involvement. Methods: Numbers of sample are 60 cases(male 46, female 14, median age: 61.5 years). According to pathology, squamous cancer 41, large cell cancer 2, adenocarcinoma 17. According to TNM stage, I 23, III 24, IIIA 13. Results : Mean long diameter of lymph node involvement is 16.0($\pm8.0$) mm in non-adenocarcinoma group, and that of adenocarcinoma group is 12.0($\pm3.2$) mm(p<0.05). If long diameter of lymph node larger than 15mm as involvement criterion is applied, sensitivity, specificity, positive predictive index, negative predictive index, accuracy of nonadenocarcinoma group are 54%, 100%, 100%, 83%, 86%, and those of adenocarcinoma group are 43%, 90%, 75%, 69%, 71%. If long diameter of lymph node larger than 10mm as involvement criterion is applied, sensitivity, specificity, positive predictive index. negative predictive index. accuracy of nonadenocarcinoma group are 65%, 77%, 61%, 92%, 79%, and those of adenocarcinoma group are 100%, 80%, 78%, 100%, 88%. Conclusion: Long diameter of lymph node larger than 10mm is more valuable criterion as lymph node involvement in adenocarcinoma of lungs.