• Transactions of the Korean Society of Mechanical Engineers
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• 제19권5호
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• pp.1259-1268
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• 1995

The stress distribution around micro holes and the behavior of stress interaction between micro holes are considerd in the study. Several conclusions are extracted as follows : (1) The stress interaction varies with the distance e between micro holes. When the two micro holes are spaced in such a manner that theri two closest points are separated by a distance of micro hole radius (e=1), stress distribution is affected by a opposite micro hole in all the closest region. In addition, if two closest points are seperated by twice the distance of a micro hole radius (e=2), stress distribution is affected by a opposite micro hole in the region of -0.8.leq.x/r.leq.0.8 and the interaction effect can be neglected for e=4. (2)If the depth becomes larger than the radius, or the radius varies, the shape and magnitude of stress distribution around micro holes varies. (3) Hoop stress around a micro hole for the two dimensional configuration is larger than that of the three dimensional micro hole located on the surface of material for .theta. < 60.deg., but it is reversed for .theta > 60.deg.

• Journal of Internet Computing and Services
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• 제19권5호
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• pp.123-131
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• 2018

A virtual team consists of various members with a range of professional skills. An IT virtual team can confer such advantages as improving creativity and solving problems in e-business. However, virtual teams are less cohesive than off-line based teams, at least partly because they do not meet face-to-face to solve problems. If the cohesion of the members in a team is weak, overall performance can decrease. Therefore, this study seeks to understand the specific types of leadership needed to increase the cohesiveness of the members in a virtual team. Leadership is the most important factor for the successful operation of a virtual team. Leaders engage members with goals, and motivate them by creating positive relationships. This study describes the idealized influence of transformational leadership in which a leader directly engages members in a goal, and the role of participative goal setting in which members set their own goals. In addition, this research demonstrates the benefits of a positive attitude of a leader towards their team members and the influence of leader-member exchanges. If the cohesion of virtual teams is improved through specific leadership, the team members will be more committed to their teams and work, and the team's performance will improve. Furthermore, the successful operation of virtual teams will provide an opportunity for companies in e-business to gain a competitive advantage in the contemporary environment, where creativity is important.

• Journal of applied mathematics & informatics
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• 제24권1_2호
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• pp.437-448
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• 2007

Suppose K is a nonempty closed convex nonexpansive retract of a real uniformly convex Banach space E with P as a nonexpansive retraction. Let $T_1,\;T_2\;and\;T_3\;:\;K{\rightarrow}E$ be nonexpansive mappings with nonempty common fixed points set. Let $\{\alpha_n\},\;\{\beta_n\},\;\{\gamma_n\},\;\{\alpha'_n\},\;\{\beta'_n\},\;\{\gamma'_n\},\;\{\alpha'_n\},\;\{\beta'_n\}\;and\;\{\gamma'_n\}$ be real sequences in [0, 1] such that ${\alpha}_n+{\beta}_n+{\gamma}_n={\alpha}'_n+{\beta'_n+\gamma}'_n={\alpha}'_n+{\beta}'_n+{\gamma}'_n=1$, starting from arbitrary $x_1{\in}K$, define the sequence $\{x_n\}$ by $$\{zn=P({\alpha}'_nT_1x_n+{\beta}'_nx_n+{\gamma}'_nw_n)\;yn=P({\alpha}'_nT_2z_n+{\beta}'_nx_n+{\gamma}'_nv_n)\;x_{n+1}=P({\alpha}_nT_3y_n+{\beta}_nx_n+{\gamma}_nu_n)$$ with the restrictions $\sum^\infty_{n=1}{\gamma}_n<\infty,\;\sum^\infty_{n=1}{\gamma}'_n<\infty,\; \sum^\infty_{n=1}{\gamma}'_n<\infty$. (i) If the dual $E^*$ of E has the Kadec-Klee property, then weak convergence of a $\{x_n\}$ to some $x^*{\in}F(T_1){\cap}{F}(T_2){\cap}(T_3)$ is proved; (ii) If $T_1,\;T_2\;and\;T_3$ satisfy condition(A'), then strong convergence of $\{x_n\}$ to some $x^*{\in}F(T_1){\cap}{F}(T_2){\cap}(T_3)$ is obtained.

• Journal of the Ergonomics Society of Korea
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• 제25권1호
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• pp.43-49
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• 2006

A laboratory study was conducted to evaluate if two different age groups(young vs. old) had differences in walking velocity and heel contact velocity and, furthermore, if these gait characteristics could adversely influence initial friction demand characteristics(i.e. RCOF) and the likelihood of slip-initiation. Twenty eight(14 younger and 14 older adults) participated in the study. While wearing a safety harness, all participants walked at their preferred gait speed for approximately 20 minutes on the linear walking track(1.5m× 20m) consisting of two floor-mounted forced plates. During subsequent 20 cameras, respectively. The results indicated that older adults walked slower(i.e., slower whole body center-of-mass velocity), exhibited lower heel contact velocity, and produced lower initial friction demand characteristics (i.e. RCOF) in comparison to younger adults. However, ANCOVA indicated that the diferences in heel contact velocity between the two age groups were due to the effects of walking velocity. The bivariate analysis further suggested that walking velocity was correlated to RCOF and heel contact velocity, while heel contact velocity was not found to be correlated to RCOF. In conclusion, could be a better indicator for predicting initial friction demand characteristics(i.e. RCOF) not hel contact velocity.

• Bulletin of the Korean Mathematical Society
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• 제39권2호
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• pp.289-297
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• 2002

It was shown by L. Polterovich ([3]) that if L is a totally real submanifold of a symplectic manifold $(M,\omega)$ and L is parallelizable then L is normal. So we try to find an answer to the question of whether there is a compatible almost complex structure J on the symplectic vector bundle $TM$\mid$_{L}$ such that $TL{\cap}JTL=0$ assuming L is normal and parallelizable. Although we could not reach an answer, we observed that the claim holds at the vector space level. And related to the question, we showed that for a symplectic vector bundle $(M,\omega)$ of rank 2n and $E=E_1{\bigoplus}E_2$, where $E=E_1,E_2$are Lagrangian subbundles of E, there is an almost complex structure J on E compatible with ${\omega}$ and $JE_1=E_2$. And finally we provide a necessary and sufficient condition for a given embedding into a symplectic manifold to be normal.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2009년도 추계학술대회 및 정기총회
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• pp.44-56
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• 2009

$Epichlo\ddot{e}$ endophytes, including Neotyphodium spp. and $Epichlo\ddot{e}$ spp., enhance plant growth, mediate more plant tolerance or resistance to biotic and abiotic stresses, and also synthesis various biologically active compounds in their host plants, and important in many areas. In early stages, most of $epichlo\ddot{e}$ endophytes were described during surveys practiced by American, European and Oceania scientists, while fungal endophytes within native Asian plants were poorly investigated. In recent years, an $Epichlo\ddot{e}$ sp. and 4 Neotyphodium spp. were described in cool season Chinese native gramineous plants. Most of Chinese native Neotyphodium spp. were presumed as hybrids originated from members of ETC and EBY. Investigation on NRPS genes shows lack of toxic ergopeptines and potential production of peramine. Biological and ecological roles of Chinese native $epichlo\ddot{e}$ endophytes should be investigated in future, and it will be very valuable if we can have some joint projects with Korean scientists for Asian native $epichlo\ddot{e}$ endophytes.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2003년도 하계학술대회
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• pp.272-277
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• 2003

Two antennas system which is aligned in cross direction is tested and analyzed. The main scope is focused to get an appropriated distance between the two small antennas to get a better property. The theoretical expectation and the computer simulation are executed simultaneously. The target is the folded IF antenna system printed on PCB, but the ideal dipole-antenna arrangement is also tested to verify the possibility of our implementation. And it is finally proved by experiments.

• Journal of applied mathematics & informatics
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• 제36권3_4호
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• pp.237-244
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• 2018

Let ${\mathcal{H}}$ be an infinite dimensional separable Hilbert space with a fixed orthonormal base $\{e_1,e_2,{\cdots}\}$. Let L be the subspace lattice generated by the subspaces $\{[e_1],[e_1,e_2],[e_1,e_2,e_3],{\cdots}\}$ and let $Alg{\mathcal{L}}$ be the algebra of bounded operators which leave invariant all projections in ${\mathcal{L}}$. Let p and q be natural numbers (p < q). Let ${\mathcal{A}}$ be a linear manifold in $Alg{\mathcal{L}}$ such that $T_{(p,q)}=0$ for all T in ${\mathcal{A}}$. If ${\mathcal{A}}$ is a Lie ideal, then $T_{(p,p)}=T_{(p+1,p+1)}={\cdots}=T_{(q,q)}$ and $T_{(i,j)}=0$, $p{\eqslantless}i{\eqslantless}q$ and i < $j{\eqslantless}q$ for all T in ${\mathcal{A}}$.

• Honam Mathematical Journal
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• 제39권1호
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• pp.93-100
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• 2017

Let $\mathcal{H}$ be an infinite dimensional separable Hilbert space with a fixed orthonormal base $\{e_1,e_2,{\cdots}\}$. Let $\mathcal{L}$ be the subspace lattice generated by the subspaces $\{[e_1],[e_1,e_2],[e_1,e_2,e_3],{\cdots}\}$ and let $Alg{\mathcal{L}}$ be the algebra of bounded operators which leave invariant all projections in $\mathcal{L}$. Let p and q be natural numbers($p{\leqslant}q$). Let $\mathcal{B}_{p,q}=\{T{\in}Alg\mathcal{L}{\mid}T_{(p,q)}=0\}$. Let $\mathcal{A}$ be a linear manifold in $Alg{\mathcal{L}}$ such that $\{0\}{\varsubsetneq}{\mathcal{A}}{\subset}{\mathcal{B}}_{p,q}$. If $\mathcal{A}$ is an ideal in $Alg{\mathcal{L}}$, then $T_{(i,j)}=0$, $p{\leqslant}i{\leqslant}q$ and $i{\leqslant}j{\leqslant}q$ for all T in $\mathcal{A}$.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• 제69권
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• pp.655-672
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• 2016

The main objective of this study is to examine the mediating effect of 'e-trust' on the relationship between the antecedents related to e-marketplace and the intention of using e-marketplace. Data was collected from a survey of 169 exporting firms in Gwangju, Korea. The results of the study are as follows ; First, 'e-trust' is produced a mediating effect when technology and government factors affect the intention of using e-marketplace. However, "e-trust" does not play a mediating role in the relationship between company factor and the intention of using e-marketplace. Second, technology factor, government factor and company factor have a positive impacts on the intention of using e-marketplace. Accordingly, in order to enhance the intention of using e-marketplace, small & medium exporting firms in Korea should try more to prepare for factors related to technology and company. In addition to these, government should give full support to be prepared for regulations and systems related to e-marketplace. If e-trust were properly built, the enhancement of using e-marketplace would be taken place more smoothly. So most of exporting firms can participate in e-marketplace more actively.