• Structural Engineering and Mechanics
• /
• v.14 no.5
• /
• pp.595-610
• /
• 2002

This paper presents an efficiency of various non-conforming (NC) modes in development of a series of new finite elements with the special emphasis on 4-node quadrilateral elements. The NC modes have been used as a key scheme to improve the behaviors of various types of new finite elements, i.e., Mindlin plate bending elements, membrane elements with drilling degrees of freedom, flat shell elements. The NC modes are classified into three groups according to the 'correction constants' of 'Direct Modification Method'. The first group is 'basic NC modes', which have been widely used by a number of researchers in the finite element communities. The basic NC modes are effective to improve the behaviors of regular shaped elements. The second group is 'hierarchical NC modes' which improve the behaviors of distorted elements effectively. The last group is 'higher order NC modes' which improve the behaviors of plate-bending elements. When the basic NC modes are combined with hierarchical or higher order NC modes, the elements become insensitive to mesh distortions. When the membrane component of a flat shell has 'hierarchical NC modes', the membrane locking can be suppressed. A number of numerical tests are carried out to show the positive effect of aforementioned various NC modes incorporated into various types of finite elements.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.10a
• /
• pp.3-7
• /
• 2001

In this study, the effect of WC and group IV elements on the cutting performance in turning is investigated. The composition of WC was changed from 5 to 20% to determine the effect of WC on the cutting performance of cermet tool. The more WC was added, the longer the tool life of the cermet tool was. The cermet with 20% WC showed the best fracture toughness. The cermet tool with 20% WC showed the best cutting performance among the various WC composition. The effect of group IV elements ; ZrC, ZrN and HfC was also investigated by adding each of them to manufacture the cermet tool with fixed 14% WC composition. The cermet with 1% group IV HfC and 14% WC showed the best cutting performance among the investigated cermet tools.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.919-922
• /
• 1997

In this study, the amount of WC and group N elements of Ti(C, N) cermet tool was investigated. The composition of WC was changed from 5 to 20% to determine the effect of WC on the cutting performance of cermet tool. The more WC was added, the longer the tool life of the cermet tool was. The cermet with 20% WC showed the best fracture toughness. The effect of group N elements ; ZrC, ZrN and HfC was also investigated by adding each of them to manufacture the cermet tool with fixed 14% WC composition. The cermet with 1% group N ZrC and 14% WC showed the best cutting performance among the investigated cermet tools.

• Bulletin of the Korean Chemical Society
• /
• v.24 no.6
• /
• pp.832-836
• /
• 2003

To extend the knowledge of triple bonding between group 6 transition metal and heavier group 14 elements, the structural and bonding aspects of ($η^5-C_5H_5$)$(CO)_2$M≡ER (M = Cr, Mo, W; E = Si, Ge, Sn, Pb) are investigated by hybrid density functional calculations at the B3PW91 level. Substituent effects are also investigated with R = H, Me, $SiH_3$, Ph, $C_6H_3-2,6-Ph_2$, $C_6H_3-2,6-(C_6H_2-2,4,6-Me_3)_2$, and $C_6H_3-2,6-(C_6H_2-2,4,6- iPr_3)_2$.

• The Journal of the Korea Contents Association
• /
• v.14 no.3
• /
• pp.509-521
• /
• 2014

The purpose of this study is to find the correlation between elements of resilience and small group activities in the university, and to explore small group activities as a protective and a positive factor in controlling the stress of college students. As the first part of the study, positive roles of resilience to the stress of college students and the elements that promote the efficiency of resilience are analyzed. The study precedent in detail and four elements of resilience are presented as following; optimistic realism, vitality, ability to control emotion, and interpersonal ability, addressing the faith in God is one of the strong positive factors for developing resilience. Then, this study deals with how the four elements of resilience relates to the characteristics of small group activities. In conclusion, this study suggests Christian universities to develop small group activities because they can develop each of the four elements of resilience of college students. Christian universities have a missional duty and the responsibility to help college students experience real happiness in their lives. Therefore, if Christian universities understand the effectiveness of resilience of college students and find out the correlation between resilience and faith, they can help students not only to live a positive life in their generation, but also to experience the authentic happiness.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.1
• /
• pp.179-187
• /
• 2013

We describe newly developed software named KPACK for relativistic electronic structure computation of molecules containing heavy elements that enables the two-component ab initio calculations in Kramers restricted and unrestricted formalisms in the framework of the relativistic effective core potential (RECP). The spin-orbit coupling as relativistic effect enters into the calculation at the Hartree-Fock (HF) stage and hence, is treated in a variational manner to generate two-component molecular spinors as one-electron wavefunctions for use in the correlated methods. As correlated methods, KPACK currently provides the two-component second-order M${\o}$ller-Plesset perturbation theory (MP2), configuration interaction (CI) and complete-active-space self-consistent field (CASSCF) methods. Test calculations were performed for the ground states of group-14 elements, for which the spin-orbit coupling greatly influences the determination of term symbols. A categorization of three procedures is suggested for the two-component methods on the basis of spin-orbit coupling manifested in the HF level.

• Journal of the Korean Institute of Educational Facilities
• /
• v.23 no.6
• /
• pp.14-16
• /
• 2016

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.1
• /
• pp.144-150
• /
• 2003

When WC and group IV elements are added to Ti(C,N)-Ni substrate, microstructures of the cermet is changed. The microstructure gives direct effect on the property of the material. In this study, the amount of WC and group W elements of Ti(C,N) cermet tool was investigated. The composition of WC was changed from 5 to 20wt% to determine the effect of WC on the cutting performance of cermet tool. The more WC was added, the longer the tool life of the cermet tool was. The cermet with 20wt% WC showed the best fracture toughness. The effect of group W elements; ZrC, ZrN and HfC was also investigated by adding each of them to manufacture the cermet tool with fixed l4wt% WC composition. The cermet with 1wt% ZrC and 14wt% WC showed the best cutting performance among the investigated cermet tools.

• Korean Journal of Applied Biomechanics
• /
• v.21 no.1
• /
• pp.17-24
• /
• 2011

The Youth Olympic Games(YOG) is an international multi-sport event first held in Singapore from August 14 to August 26, 2010. The idea for such an event was introduced by International Olympic Committee(IOC). The Federation of International Gymnastics(2009) designed the Code of Points and regulates for junior gymnastics at this time. The purpose of this study was to give crucial information and adapt to coaches and junior gymnasts at the time of changing code rapidly. For this study, The eight finalists rings exercise at the 1st Youth Olympic Games was recorded using a digital camcoder. The exercise contents analysis of rings was carried out by an experienced international judge using Code of Points(FIG, 2009). The C elements in various difficulties were performed the highest frequency. The elements group I was the most frequently performed in overall difficulties. Moreover, All the gymnasts performed the elements of the Jonasson and Yamawaki in Group I. Therefore, junior gymnasts need to consider Jonasson and Yamawaki elements correctly in elements group I. The 1st ranked ROU(132) gymnast performed high difficulty value for his routine with the highest E score(9.050). The average of D score were 5.125. In the E scores, 8th USA(140) gymnast received the lowest E score of 8.15, 5th MGL(127) gymnasts received the fewer E score of 8.475. Coaches and junior gymnasts should try to increase D score above 5.125 by higher swing elements in Group I and II as well, decrease deduction of elements in exercise contents.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.12
• /
• pp.1225-1230
• /
• 2014

This paper investigates the group average-consensus and group formation-consensus problems for first-order multi-agent systems. The control protocol for group consensus is designed by considering the positive adjacency elements. Since each intra-group Laplacian matrix cannot be satisfied with the in-degree balance because of the positive adjacency elements between groups, we decompose the Laplacian matrix into an intra-group Laplacian matrix and an inter-group Laplacian matrix. Moreover, average matrices are used in the control protocol to analyze the stability of multi-agent systems with a fixed and undirected communication topology. Using the graph theory and the Lyapunov functional, stability analysis is performed for group average-consensus and group formation-consensus, respectively. Finally, some simulation results are presented to validate the effectiveness of the proposed control protocol for group consensus.