• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.485-491
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• 1999

A burr is formed in every corner of parts as a result of machining, which produces undesirable edge geometry and influence deeply to surface quality of workpiece. Therefore these burrs must be removed certainly. The cost of removing these burrs is directly proportional to their size. Burrs have been among the most troublesome obstruction to high productivity and automation of machining processes. The proper selection of cutting condition and tool geometry will be helpful to reduce the occurrence of burrs. In paper will observe burr formation along helix angle in end milling and certificate experimentally mechanics relation of helix angle and burr formation.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.2
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• pp.17-24
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• 2004

In end milling process, undeformed chip thickness and cutting forces vary periodically with phase change of the tool. Recently, a model has been proposed to simulate the shear and friction characteristics of an up-end milling process in terms of the equivalent oblique cutting to this. In the current study, a down-end milling process has been replaced with the equivalent oblique cutting process. And shear and tool-chip friction characteristics variation of SM45C steel has been studied using the end-mills of different helix angles. The specific shear and friction energy consumed with helix angle of $50^{\circ}$ is somewhat larger than those of$30^{\circ}$ and $40^{\circ}$. The specific shear energy consumed is about 76-77% of the specific cutting energy regardless the helix angles.

• Kyungpook Mathematical Journal
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• v.56 no.3
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• pp.1003-1016
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• 2016

In this paper, we introduce a new kind of slant helix for null curves called null $W_n$-slant helix and we give a definition of new harmonic curvature functions of a null curve in terms of $W_n$ in (n + 2)-dimensional Lorentzian space $M^{n+2}_1$ (for n > 3). Also, we obtain a characterization such as: "The curve ${\alpha}$ s a null $W_n$-slant helix ${\Leftrightarrow}H^{\prime}_n-k_1H_{n-1}-k_2H_{n-3}=0$" where $H_n,H_{n-1}$ and $H_{n-3}$ are harmonic curvature functions and $k_1,k_2$ are the Cartan curvature functions of the null curve ${\alpha}$.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2460-2464
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• 2008

The present paper suggests new method to know the effects of molecular diffusion and the helicity of microchannel flows on mixing in passive micromixers, which are essential components of a microfluidic chip. In this study, 'Helix Index' is newly defined as the magnitude of chaotic advection. Relationship between Helix Index and Mixing Index is analyzed numerically such as the wide range of Peclet and Reynolds numbers in three dimensional serpentine microchannel when using soluble solutions (water/glycerol). As a result, a simple algebraic equation is derived by this relationship based on a regression analysis. The algebraic equation is found to be able to accurately predict the mixing performance without solving the coupled, complex momentum and mass transfer equations.

• Bulletin of the Korean Chemical Society
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• v.17 no.2
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• pp.131-138
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• 1996

The conformational transition of oligopeptide multimer,-(HPPHPPP)n-, is studied (H:hydrophobic amino acid, P:hydrophilic amino acid). The helix/coil transitions are detected in the multimer. The transition depends on the number of amino acid in the sequence, the concentration of the oligopeptide, and temperature which affects helix stability constant (${\xi}$) and hydrophobic interaction parameter (wj). In the thermodynamic equilibrium system jA${\rightarrow}$Aj (where A stands for oligopeptide monomer), Skolnick et al., explained helix/coil transition of dimer by the matrix method using Zimm-Bragg parameters ${\xi}$ and $\sigma$ (helix initiation constant). But the matrix method do not fully explain dangling H-bond effects which are important in oligopeptide systems. In this study we propose a general theory of conformational transitions of oligopeptides in which dimer, trimer, or higher multimer coexists. The partition of trimer is derived by using zipper model which account for dangling H-bond effects. The transitions of multimers which have cross-linked S-S bonds or long chains do not occur, because they keep always helical structures. The transitions due to the concentration of the oligopeptides are steeper than those due to the chain length or temperature.

• Journal of Contemporary Eastern Asia
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• v.13 no.1
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• pp.1-4
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• 2014

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.2
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• pp.183-195
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• 2016

Although we have faced substantial public interests on the issues of small-business, the lack of effective solutions corresponding to them should be worried. This paper introduces findings from the application of Triple Helix to counseling activities for small-business stores with diagnosing problems and suggesting alternatives. The findings of this paper are based on counseling projects conducted by Gyunggi Small-medium Business Corporation, universities in the region, and multiple small-business stores together from June to November in 2015. The application of Triple Helix was positive for increasing the effectiveness of counseling, and this key finding was obtained from action research cycles. It was also confirmed that cooperation from three different entities including company, university and government institute was beneficial in increasing problem identification capabilities by students and providing opportunities for testing knowledge and skills, which means Triple Helix application to small-business helps management education to be more practical. Contributions of this study supplies substantial insights to academic audience, and practitioners can learn positive effects of Triple Helix and potential issues for implementation in the context of small-business counseling.

• BMB Reports
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• v.28 no.3
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• pp.221-226
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• 1995

Dopamine mediates inhibitory responses in Helix aspersa neurons from the right parietal lobe ("F-lobe") of the circumoesophageal ganglia. The effects appeared as a dose-dependent hyperpolarization of the plasma membrane and a decrease in the occurrence of spontaneous action potentials. The average hyperpolarization with 5 ${\mu}m$ dopamine was -12 mV (${\pm}1.5$mV, S.D., n=12). Dopamine also modulated the currents 'responsible for shaping the action potentials in these neurons. When dopamine was added and action potentials were triggered by an injection of current, the initial depolarization was slowed, the amplitude and the duration of action potentials were decreased, and the after-hyperpolarization was more pronounced. The amplitude and the duration of action potential were reduced about 15 mV and about 13% by 5 ${\mu}m$ dopamine, respectively. The effects of dopamine on the resting membrane potentials and the action potentials of Helix neurons were dose-dependent in the concentration range 0.1 ${\mu}m$ to 50 ${\mu}m$. In order to show 1) that the effects of dopamine were mediated by dopamine receptors rather than by direct action on ionic channels and 2) which type of dopamine receptor might be responsible for the various effects, we assayed the ability of mammalian dopamine receptor antagonists, SCH-23390 (antagonist of D1 receptor) and spiperone (antagonist of D2 receptor), to block the dopamine-dependent changes. The D1 and D2 antagonists partially inhibited the dopamine-dependent hyperpolarization and the decrease in action potential amplitude. They both completely blocked the decrease in action potential duration and the increase in action potential after-hyperpolarization. The dopamine-induced slowdown of the depolarization in the initial phase of the action potentials was less effected by SCH-23390 and spiperone. From the results we suggest 1) that Helix F-lobe neurons may have a single type of dopamine receptor that binds both SCH-23390 and spiperone and 2) that the dopamine receptor of Helix F-lobe neurons may be homologous with and primitive to the family of mammalian dopamine receptors.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.229-233
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• 2016

In this paper, we present the four genetic nitrogenous bases of C, U(T), A, G to matrices and describe the structures from $4{\times}4$ RNA(ribose nucleic acid) to $8{\times}8$ DNA((deoxyribose nucleic acid) matrices. we analysis a deoxyribose nucleic acid (DNA) double helix based on the block circulant Hadamard-Jacket matrix (BCHJM). The orthogonal BCHJM is anti-symmetric pair complementary of the core DNA. The block circulant ribonucleic acid (RNA) repair damage reliability is better than the conventional double helix. In case of k=4 and N=1, the reliability of block circulant complementarity is 93.75%, and in case of k=4 and N=4, it is 98.44%. Therefore it improves 4.69% than conventional case of double helix.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.4
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• pp.801-816
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• 2014

This paper is a theoretically grounded empirical study aimed at shedding light on the Triple Helix of University-Industry-Government (U-I-G) relations in biotechnology cluster of Singapore. It questions the issue about the gap between theoretical consideration of the Triple Helix of U-I-G relations and the actual reality in biotechnology cluster, and the experience of Singapore was investigated. In terms of evolutionary perspective, biotechnology cluster in Singapore has gone through ongoing processes from a certain stage to other, and within the processes the Triple Helix nexus has been found. Analysis of the empirical study reveals significant findings: first, the government policies play a critical role in the operation of U-I-G relations rather than universities; second, therefore, the binding force of U-I-G relationships is based on the government policies being comprehensive including researchers immigration, student scholarship for local students, and tax and non-tax incentives for firms, rather than focusing on a targeted policy; third, the role of government starts from an initial stage, and it's role is ongoing processes by supporting infrastructure, human sources and continuous nourishment enabling the triple helix of U-I-G relations.