• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.7
• /
• pp.3690-3713
• /
• 2019

According to the main group key management schemes logical key hierarchy (LKH), exclusion basis systems (EBS) and other group key schemes are limited in network structure, collusion attack, high energy consumption, and the single point of failure, this paper presents a group key management scheme for wireless sensor networks based on Lagrange interpolation polynomial characteristic (AGKMS). That Chinese remainder theorem is turned into a Lagrange interpolation polynomial based on the function property of Chinese remainder theorem firstly. And then the base station (BS) generates a Lagrange interpolation polynomial function f(x) and turns it to be a mix-function f(x)' based on the key information m(i) of node i. In the end, node i can obtain the group key K by receiving the message f(m(i))' from the cluster head node j. The analysis results of safety performance show that AGKMS has good network security, key independence, anti-capture, low storage cost, low computation cost, and good scalability.

• The Journal of Pediatrics of Korean Medicine
• /
• v.16 no.2
• /
• pp.171-185
• /
• 2002

Objectives : The purpose of this study was to investigate the spine distortion and self-conscious pain in high school students. Method : Using the phase-shifting moire developed by KAIST(Korea Advanced Institute of Science and Technology) we measured the back surface distortion, and using questionnaire investigation, we investigated the self-conscious pain in 30 high school students(17 boy students and 13 girl students). Results : This study show that low back pain was most cases, and next headache, upper back pain, abdominal pain, neck pain, shoulder pain, leg pain, chest pain and gluteal pain. The ratio of each self-conscious pain was 90.0%, 86.7%, 83.3%, 83.3%, 80.0%, 76.7%, 66.7%, 33.3%, 33.3%, 30.0%. In remainder value of left and right shoulder, above of 3.0 were three students., above 2.0 to bellow 3.0 were 10 students, bellow 2.0 were 17 students. In remainder value of left and right gluteal, above of 2.0 was one students, above 1.0 to bellow 2.0 were 18 students, bellow 1.0 were 10 students. In remainder value of cervical vertical line to left and right axillae, above 4.0 was 1 student, above 3.0 to bellow 2.0 were 2 students, above 2.0 to bellow 3.0 were 3 students, above 1.0 to bellow 2.0 were 16 students, bellow 1.0 were 7 students. In remainder value of gluteal vertical line to left and right axillae, above 6.0 was 1 student, above 5.0 to bellow 6.0 were 7 students, above 4.0 to bellow 5.0 were 3 students, above 3.0 to bellow 4.0 were 2 students, above 2.0 to bellow 3.0 were 5 students, above 1.0 to bellow 2.0 were 7 students, bellow 1.0 were 5 students. In remainder value of cervical vertical line to gluteal vertical line, above 40 was 1 student, above 3.0 to bellow 4.0 were 4 students, above 3.0 to bellow 3.0 were 6 students, above 1.0 to bellow 2.0 were 8 students, bellow 1.0 were 11 students. Conclusion : It is suggested that the significant correlation exist between the spinal distortion and self-conscious pain. And we can find many cases as spinal distortion in high school students also. We have to study further more about juvenile postural distortion and it's prevention.

• Journal for History of Mathematics
• /
• v.8 no.1
• /
• pp.54-60
• /
• 1995

No Abstract, See Full Text

• Journal for History of Mathematics
• /
• v.1 no.1
• /
• pp.80-82
• /
• 1984

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.12
• /
• pp.1886-1896
• /
• 2004

Various types of buckets are used as unloading facilities for raw material at unloading wharfs. Scissors type buckets, among them, has been being used widely because of their short cycle time and structural simplicity. However, the scooping capacity, especially for hardened remainder ore, of some buckets are unsatisfactory because of poor design concept of the buckets. In this study, the effects of the design parameters on the scooping performance of the buckets are investigated under kinematic and dynamic analysis. Further, the schemes and design guidelines for designing new scissors type buckets are also presented to improve ore scooping capacity for hardened remainder ore.

• Bulletin of the Korean Mathematical Society
• /
• v.31 no.1
• /
• pp.93-97
• /
• 1994

Previously T.Porter [3] has given a relative Chinese Remainder Theorem under the hypothesis that given ring R has at least one .tau.-closed maximal ideal (by his notation Ma $x_{\tau}$(R).neq..phi.). In this short paper we drop his overall hypothesis that Ma $x_{\tau}$(R).neq..phi. and give the proof and some related results with this Theorem. In this paper R will always denote a commutative ring with identity element and all modules will be unitary left R-modules unless otherwise specified. Let .tau. be a given hereditarty torsion theory for left R-module category R-Mod. The class of all .tau.-torsion left R-modules, dented by J is closed under homomorphic images, submodules, direct sums and extensions. And the class of all .tau.-torsionfree left R-modules, denoted by F, is closed under taking submodules, injective hulls, direct products, and isomorphic copies ([2], Proposition 1.7 and 1.10).

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.1148-1153
• /
• 2003

An adequate method for the prediction of machining errors is essential to improve productivity and product quality. But it is known that there is a remarkable difference between values calculated by conventional roughness model and measured values of actual machined surfaces under high efficient cutting condition. This paper introduces the theoretical analysis of characteristic lines of cut remainder to evaluate a geometrical surface roughness accurately. In this study, analytic equations of the characteristic lines are derived from the surface generation mechanism of ball end milling considering the actual trochoidal trajectories of cutting edges. The predicted results are compared with the results of conventional roughness model.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.66-69
• /
• 2003

This paper presents the procedures for the evaluation of the maximum surface roughness and the shapes of the cut remainder employing the ridge method. The shapes and the heights of the cut remainder are estimated by overlapping adjacent ridges in consideration of the various machining parameters: the feedrate. the path interval. The maximum surface roughness in plane cutting modes are derived as a function of the maximum effective cutter radius, R$\_$eff,max/. and the path interval ratio, $\tau$$\_$fp/, The predicted results are compared with the values estimated by the conventional roughness model.

• The Mathematical Education
• /
• v.52 no.2
• /
• pp.217-230
• /
• 2013

This study attempts to propose the construction of textbook contents of fraction division and to suggest a method to strengthen the connection among problem context, manipulation activities and symbols by proposing an algorithm of dividing fractions based on problem contexts. As showing the suitable algorithm to problem context, it is able to understand meaningfully that the algorithm of fractions division is that of multiplication of a reciprocal. It also shows how to deal with remainder in the division of fractions. The results of this study are expected to make a meaningful contribution to textbook development for primary students.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.367-368
• /
• 2015

This paper evaluates performance degradation of an NG-EPON (1next-generation Ethernet-passive opticla network) system due to an unused remainder of a grant. Since a packet segmentation is not permitted in NG-EPON, a grant is wasted if the grant size is less than the packet size. Using simulations, we evaluate performance degradation due to the unused remainder.