• Bulletin of the Korean Mathematical Society
• /
• v.53 no.5
• /
• pp.1309-1325
• /
• 2016

This note focuses on a ring property in which upper and lower nilradicals coincide, as a generalizations of symmetric rings. The concept of symmetric ideal and ring in the noncommutative ring theory was initially introduced by Lambek, as an extension of the usual commutative ideal theory. The investigation of symmetric rings provided many useful results to the study in the noncommutative ring theory. So the results obtained from this study may be applicable to observing the structure of zero divisors in various kinds of algebraic systems containing matrix rings and polynomial rings.

• Communications for Statistical Applications and Methods
• /
• v.7 no.3
• /
• pp.845-858
• /
• 2000

In this paper new results are obtained for multivariate processes which help us to identify weak negative orthant dependent(WNOD) structures among hitting times of the processes. Furthermore, an approach to derive dependence properties among the processes is proposed and a partial solution to the question tat what kinds of the dependence properties, when they are imposed on processes, are reflected as analogous properties of corresponding hitting times is give. Examples are given to illustrate these concepts.

• Journal of the Korean Statistical Society
• /
• v.4 no.1
• /
• pp.67-78
• /
• 1975

Over twenty-five years ago, Professor Klein and Rubin presented the linear expenditure system. That system was first estimated by Stone. Subsequently many investigators have estimated that system. In this paper, many points of the error structure shown by Pollak and Wales are referred to. Barten presented an estimation theorem on a singular covariance matrix. In order to estimate parameters, we place an emphasis on the maximum likihood method which we believe to be most appropriate. As we have one linear restriction on parameters to be estimated, we maximized the associated likelihood function subject to that linear restriction through the well-known lagrange multiplier method. This paper is organized in the following fashion : (1) a brief description on classical consumer theory, (2) a linear expenditure system and its constraint, (3) dyanmic specification and stochastic specification, (4) estimation method, and (5) conclusion.

• Journal of the Korean Society of Physical Medicine
• /
• v.2 no.2
• /
• pp.219-228
• /
• 2007

Objective : The purpose of this study was conducted to find treatment of forward head posture and shoulder instability with proprioceptive neuromuscular facilitation concept. Methods : This is literature study with books, seminar note and international course. Results : Forward head posture and shoulder instability has related each other. Forward head posture will make muscle instability, weakness and stiffness on neck and shoulder girdle. It will make pain also. Important muscle are suboccipital muscle, omohyoid muscle, sternoclaidomastoid muscle, scaleni, pectoralis minor, levator scapular and digastric. Conclusion : Treatment of the forward head posture and shoulder instability is provided. It is that treatment of stiff muscle with eccentric muscle work, muscle elongation, muscle strengthening at the structure level and at the functional level for daily activities.

• Journal of the military operations research society of Korea
• /
• v.22 no.1
• /
• pp.1-17
• /
• 1996

In this paper, a client/server architecture and design concerns deduced from a real system design are described. The MIS system carried on IDIS is the one to be described. The experience from the system design is listed up and analized also. It is common to see that a distributed computing environment has much more complex structure than a conventional centralized one. As a consequence, a distributed system design is a complex task. It is worth to note that there should be sufficient considerations which had not been though ever for a centralized system. The objectives of this paper is to list up these problems and the solutions from experiences on a real system construction.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.11
• /
• pp.1612-1619
• /
• 2017

In this note, a complete proof of Utkin's theorem is presented for SI(single input) uncertain nonlinear systems. The invariance theorem with respect to the two nonlinear transformation methods so called the two diagonalization methods is proved clearly, comparatively, and completely for SI uncertain nonlinear systems. With respect to the sliding surface and control input transformations, the equation of the sliding mode i.e., the sliding surface is invariant, which is proved completely. Through an illustrative example and simulation study, the usefulness of the main results is verified. By means of the two nonlinear transformation methods, the same results can be obtained.

• PNF and Movement
• /
• v.5 no.2
• /
• pp.1-10
• /
• 2007

Purpose : The purpose of this study was conducted to find treatment of forward head posture and shoulder instability with proprioceptive neuromuscular facilitation concept. Methods : This is literature study with books, seminar note and international course. Results : Forward head posture and shoulder instability has related each other. Forward head posture will make muscle instability, weakness and stiffness on neck and shoulder girdle. It will make pain also. Important muscle are suboccipital muscles, omohyoid muscle, sternoclaidomastoid muscle, scaleni, pectoralis minor, levator scapular and digastric. Conclusion : Treatment of the forward head posture and shoulder instability is provided. It is that treatment of stiff muscle with eccentric muscle work, muscle elongation, muscle strengthening at the structure level and at the functional level for daily activities.

• PNF and Movement
• /
• v.2 no.1
• /
• pp.49-57
• /
• 2004

Objective : The purpose of this study was conducted to find treatment approach, functional test process with proprioceptive neuromuscular facilitation(PNF). Method : This is a literature study with books, seminar note and book for PNF international course. Result : Suggest of the functional test with functional level and structural level treatment approaching with hypotheses and problem list from the functional test and provide how, what, where for the treatment with the level. Conclusion : Treatment plan and approach has changed from disease to structure function, performance, participation the life, relationship with environment factors of human being. For the treatment approach need the functional test and functional goal.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.2
• /
• pp.108.1-108.1
• /
• 2012

Previously we introduced ray-tracing based 3D optical earth system model for specular and scattering properties of all components of the system (i.e. clear-sky atmosphere, land surfaces and an ocean surface). In this study, we enhanced 3-dimensional atmospheric structure with vertical atmospheric profiles for multiple layer and cloud layers using Lambertian and Mie theory. Then the phase dependent disk averaged spectra are calculated. The main results, simulated phase dependent disk averaged spectra and light curves, are compared with the 7 bands(300~1000nm) light curves data of the Earth obtained from High Resolution Instrument(HRI) in Deep Impact spacecraft during Earth flyby in 2008. We note that the results are comparable with the observation.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.4
• /
• pp.843-847
• /
• 2011

In this note, a proof of Utkin's theorem is presented for the SI(Single Input) uncertain integral linear case. The invariance theorem with respect to the two transformation methods so called the two diagonalization methods are proved clearly and comparatively for SI uncertain integral linear systems. With respect to the sliding surface transformation, the equation of the sliding mode, the sliding surface is invariant. Both the applied control inputs have the same gains. By means of the two transformation methods the same results can be obtained. Through an illustrative example and simulation study, the usefulness of the main results is verified.