• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.1
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• pp.106-113
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• 2014

This work proposes an analytic framework to estimate the capacity of the link in an M2M gateway that multiplexes a massive number of machine type communication devices. First, we specify the network architecture for M2M communications. Next, we summarize the characteristics of M2M traffic, from which we extract an area about the problem that has to be resolved in the dimensioning of the link capacity. After that we propose a new method to determine the capacity of the link in an M2M gateway. Via numerical experiment reflecting the realistic environment of M2M traffic, we illustrate the validity of the proposed model.

• Information and Communications Magazine
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• v.27 no.7
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• pp.10-15
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• 2010

그 동안 M2M 시장은 각 분야에서 IT를 융합하다가 자연발생적으로 형성되기 시작하면서, 복잡한 Supply Chain과 Long-Tail적 사업 특성을 가져 크게 활성화되지는 못하였다. 하지만 최근 무선기술의 발달, 글로벌 시장의 성장, 비용의 하락으로 인해 새로운 전기를 맞고 있다. 이에 따라 M2M 시장에 대해 KT는 M2M 인프라 구축과 제공, M2M 시장 창출과 활성화, 정부의 M2M 관련 사업에 대한 적극적인 참여 등을 기본방향으로 하여 추진 중이다. 특히 시장 창출과 활성화를 위해 저가 범용의 M2M 모듈을 개발하고, 요금상품을 재구성하는 증 비용 절감과 함께 M2M 플랫폼을 직접 구축, 외부 사업자에 제공하여 진입장벽을 낮추며, Open Ecosystem을 통해 관련 사업주체 간에 상호 Win-Win할 수 있는 사업환경을 만들어 나가고 있다. 본 원고는 종합 통신 사업자로서의 KT가 공공의 이익과 기업의 영리를 함께 고려하면서 M2M 사업을 진행해나가는 내용을 다루고 있다.

• Journal of the Chungcheong Mathematical Society
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• v.23 no.4
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• pp.731-739
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• 2010

In this paper, we prove stability of the reciprocal difference functional equation $$r\(\frac{{\sum}_{i=1}^{m}x_i}{m}\)-r\(\sum_{i=1}^{m}x_i\)=\frac{(m-1){\prod}_{i=1}^{m}r(x_i)}{{\sum}_{i=1}^{m}{\prod}_{k{\neq}i,1{\leq}k{\leq}m}r(x_k)$$ and the reciprocal adjoint functional equation $$r\(\frac{{\sum}_{i=1}^{m}x_i}{m}\)+r\(\sum_{i=1}^{m}x_i\)=\frac{(m+1){\prod}_{i=1}^{m}r(x_i)}{{\sum}_{i=1}^{m}{\prod}_{k{\neq}i,1{\leq}k{\leq}m}r(x_k)$$ in m-variables. Stability of the reciprocal difference functional equation and the reciprocal adjoint functional equation in two variables were proved by K. Ravi, J. M. Rassias and B. V. Senthil Kumar [13]. We extend their result to m-variables in similar types.

• The Korean Journal of Ecology
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• v.15 no.4
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• pp.329-335
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• 1992

Bionomics of diplopodes was studid near chongyongchi in the chiri mountains from sept. 1990 to dec. 1991 by surveying 10 sample sites at 12 occasions. During this period 13 species of diplopodes from 11 genera, 8 families, and 6 orders were collected. Species were more diversed under quercus mongolica followed by quercus serrata and pinus densiflora sp. epenerchodus koreanus bifidus, and e. k. koreanus were found in all sample sites and these 6 species have been reported to be distributed throughout south korea. yamasinaium sp., riukiaria semicirculalis, parafontaria koreanus, and sicotanus eurygaster were found only under quercus mongolica community and postulated to be related to diet meanwhile other enviromental factors such as temperature, soil ph, and altitude should be taken into consideration. Species diversity index was higher at altitude 700m followed by at 900m, 1, 000m, 800m, 600m, 500m, 1, 100m, 400m, 300m, and 1, 200m in discending order likely due to the enviromental factors such as climatic and edaphic affects, disturbance by human, and degree of floral diversity. Species similarity index was highest 0.78 between altitude 500m and 600m sample sites could be grouped into 3, namely first 300m, 400m, second 500m, 600m, 700m, 1, 000m, 800m, 900m, and third 1, 100m, 1, 200m.

• Journal of Applied Biological Chemistry
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• v.42 no.1
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• pp.12-18
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• 1999

Sucrose synthase (EC 2.4.1.13) has been purified from the plant cytosolic fraction of chickpea (Cicer arietinum L. cv. Amethyst) nodules. The native enzyme had a molecular mass of $356{\pm}15kD$. The subunit molecular mass was $87{\pm}2kD$, and a tetrameric structure is proposed for sucrose synthase of chickpea nodule. Optimum activities in the sucrose cleavage and synthesis directions were at pH 6.5 and 9.0, respectively. The purified enzyme displayed typical hyperbolic kinetics with substrates in cleavage and synthesis reactions. Chickpea nodules sucrose synthase had a high affinity for UDP ($K_m$, $8.0{\mu}M$) and relatively low affinities for ADP ($K_m$, 0.23 mM), CDP ($K_m$, 0.87 mM), and GDP ($K_m$, 1.51 mM). The $K_m$ for sucrose was 29.4 mM. In the synthesis reaction, UDP-glucose ($K_m$, $24.1{\mu}M$) was a more effective glucosyl donor than ADP-glucose ($K_m$, 2.7 mM), and the $K_m$ for fructose was 5.4 mM. Divalent cations, such as $Ca^{2+}$, $Mg^{2+}$, and $Mn^{2+}$, stimulated the enzyme activity in both the cleavage and synthesis directions, and the enzyme was very sensitive to inhibition by $HgCl_2$ and $CuSO_4$.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1032-1037
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• 2006

This thesis studied effects of the excavation around railroads on the deformation of the lateral ground and neighboring railroads. The conclusions of the study are as follows. 1. When the depth of excavationis 10m, the influential area should be 35m for soft clay, 20m for normal clay, 15m for hard clay, 15m for loose sand, 12m for slightly dense sand, and 8m for dense sand. 2. When the influential area is 10m, the allowable excavation depth should be 2.5m for soft clay, 4.8m for normal clay, 7.5m for hard clay, 7.2m for loose sand, 8.8m for slightly dense sand, and 10m for dense sand. 3. When the influential area is 20m, the allowable excavation depth should be 4.5m for soft clay, and up to 10m for the other five kinds of soil. 4. When the influential area is 30m, the allowable excavation depth should be 7.5m for soft clay, and up to 10m for the other five kinds of soil. 5. When the influential area is 35m, the allowable excavation depth should be up to 10m for all kinds of soil.

• Journal of the Korean Mathematical Society
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• v.49 no.2
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• pp.435-447
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• 2012

Let G be a group. Let R be a G-graded commutative ring with identity and M be a G-graded multiplication module over R. A proper graded submodule Q of M is semiprime if whenever $I^nK{\subseteq}Q$, where $I{\subseteq}h(R)$, n is a positive integer, and $K{\subseteq}h(M)$, then $IK{\subseteq}Q$. We characterize semiprime submodules of M. For example, we show that a proper graded submodule Q of M is semiprime if and only if grad$(Q){\cap}h(M)=Q+{\cap}h(M)$. Furthermore if M is finitely generated then we prove that every proper graded submodule of M is contained in a graded semiprime submodule of M. A proper graded submodule Q of M is said to be almost semiprime if (grad(Q)$\cap$h(M))n(grad$(0_M){\cap}h(M)$) = (Q$\cap$h(M))n(grad$(0_M){\cap}Q{\cap}h(M)$). Let K, Q be graded submodules of M. If K and Q are almost semiprime in M such that Q + K $\neq$ M and $Q{\cap}K{\subseteq}M_g$ for all $g{\in}G$, then we prove that Q + K is almost semiprime in M.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10C
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• pp.959-964
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• 2007

In this paper, for a positive integer M and a prime p such that $M|p^n-1$, families of M-ary sequences using the M-ary Sidel'nikov sequences with period $p^n-1$ are constructed. The family has its maximum magnitude of correlation values upper bounded by $3\sqrt{p^{n}}+6$ and the family size is $(M-1)^2(2^{n-1}-1)$+M-1 for p=2 or $(M-1)^2(p^n-3)/2+M(M-1)/2$ for an odd prime p.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.333-340
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• 1999

Background: Plasminogen activator inhibitor-1(PAI-1) is known as the primary physiological inhibitor of tissue-type plasminogen activator(t-PA) in the plasma, and is present within the atherosclerotic vessels. Increased plasma levels of PAI-1 are one of the major disturbances of the hemostatic system in patients with diabetes and/or hypertension, and may have multiple interrelations with the important risk factors in the development of atherosclerosis. This study was performed to determine whether altered gene expression of PAI-1 occurs within the arterial wall, and thereby potentially contributing to the increase of cardiovascular risks associated with diabetes and/or hypertension. Material and Method: The aortic vascular smooth muscle cells of the rat were exposed to 22 mM glucose, angiotensin II, and insulin increased PAI-1 mRNA expression with the use of Northern blotting were examined. Also examined were the effects of 22 mM glucose, angiotensin II and insulin on the growth of the rat's aortic smooth muscle cells by using MTT assay. Result: Twenty-two mM glucose treatment increased the PAI-1 mRNA expression in a time- and dose-dependent manner. Aniotensin II treatment synergistically increased the glucose-induced PAI-1 mRNA expression. In contrast, addition of insulin attenuated the increase of 22 mM glucose and angiotensin II induced PAI-1 mRNA expression. Furthermore, treatment of 22 mM glucose, angiotensin II and insulin resulted in a significant increase in cell numbers. This study demonstrated that 22 mM glucose and angiotensin II have a synergistic effect in stimulating the PAI-1 mRNA expression and in the cell growth of the rat's aortic smooth muscle cells. Conclusion: Elevation of glucose and angiotensin II may be important risk factors in impairing fibrinolysis and developing atherosclerosis in diabetic patients.

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.475-479
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• 1997

The effects of amino acids and metabolites in growth media on the biosynthesis of prodigiosin from Serratia marcescens ATCC 25419 were examined. The prodigiosin synthesis was decreased approximately by 50 to 80% by several amino acids and metabolites tested. The prodigiosin synthesis was increased approximately by 20 to 40% by a low concentration of glyoxylate(1 to 3mM) and outstandingly increased by 122% at 5mM concentration under anaerobic condition. However, the prodigiosin synthesis was decreased approximately by 50 to 90% at a high concentration(20 to 30mM) under anaerobic condition. The prodigiosin was not synthesized by pyruvate and $\alpha$-ketobutyrate under aerobic and anaerobic condition, with addition to glyoxylate under aerobic condition, among the range from 0.5 to 30mM, while the cell growth under anaerobic condition was decreased distinctly by a high concentration(20mM above) of glyoxylate. These data suggest that the growth and prodigiosin of S. marcescens is positively regulated by a low concentration of glyoxylate (1-5mM), but repressed by a high concentration of glyoxylate(20mM above) unlike pyruvate and $\alpha$-ketobutyrate.