• Communications of the Korean Mathematical Society
• /
• v.39 no.3
• /
• pp.693-715
• /
• 2024

Let n ∈ ℕ, n ≥ 2. An element (x₁, . . . , x_n) ∈ Eⁿ is called a norming point of T ∈ 𝓛(ⁿE) if ||x₁|| = ··· = ||x_n|| = 1 and |T(x₁, . . . , x_n)| = ||T||, where 𝓛(ⁿE) denotes the space of all continuous n-linear forms on E. For T ∈ 𝓛(ⁿE), we define Norm(T) = {(x₁, . . . , x_n) ∈ Eⁿ : (x₁, . . . , x_n) is a norming point of T}. Norm(T) is called the norming set of T. Let $0{\leq}{\theta}{\leq}{\frac{{\pi}}{4}}$ and ${\ell}^2_{{\infty},{\theta}}={\mathbb{R}}^2$ with the rotated supremum norm $${\parallel}(x,y){\parallel}_{({\infty},{\theta})}={\max}\{{\mid}x\;cos\;{\theta}+y\;sin\;{\theta}{\mid},\;{\mid}x\;sin\;{\theta}-y\;cos\;{\theta}|\}$$. In this paper, we characterize the norming set of T ∈ 𝓛(ⁿℓ²_(∞,θ)). Using this result, we completely describe the norming set of T ∈ 𝓛_s(ⁿℓ²_(∞,θ)) for n = 3, 4, 5, where 𝓛_s(ⁿℓ²_(∞,θ)) denotes the space of all continuous symmetric n-linear forms on ℓ²_(∞,θ). We generalizes the results from [9] for n = 3 and ${\theta}={\frac{{\pi}}{4}}$.

• Journal of Gifted/Talented Education
• /
• v.5 no.2
• /
• pp.37-54
• /
• 1995

The radical development of modern mathematics is due to the appearance of Collection Theory by George Cantor. The Set Theory is independent as an area and also closely interrelated with other areas. So its content becomes a common sense and a basic part across the whole area of modern mathematics. Accordingly, the basic element of modern mathematics is helping young children get familiar with set as early as possible. The thinking of set by which children can categorize, make partial sets and correspondences, understand the general characteristic, and conceptualize the discovered relationships is very important for young children. At this point where the Math education for young children is emphasized under the influence of the modernization movement of Math education, the systematic education for building up the set concept as the basic background of number concept during the early childhood is required. On current mathematics education for young children, graphs, the foundation of geometry, time, and patterns have been included in the traditional and practical content related to numbers. However, the education on collection which is the foundation of number concept is insufficient. A study shows that the level of young children's understanding on set is quite high, but the set concept isn't reflected in current Math curriculum for young children. And basic activities neccesary on building up the set concept, such as categorization, comparison, etc. are conducted in kindergardens but unsatisfactory because of those kindergarden teachers' premature understanding on the set concept. In conclusion, the curriculum for young children should be reorganized based on the set concept as the kernel concept. Also, the reappraisal of the training curriculum and the supplementary efucation for kindergarden teachers are urgent for raising the teaching ability of those kindergarden teachers.

• 제어로봇시스템학회:학술대회논문집
• /
• 1991.10b
• /
• pp.1796-1800
• /
• 1991

Picture Archiving and Communication Systems(PACS) provide an integration of digital imaging information in a hospital, which encompasses various imaging equipment, viewing workstations, database archive systems, and a high speed fiber optic network. One of the most important requirements for integration is the standardization of communication protocols to connect devices from different vendors. Since 1985, the ACR-NEMA standard provides a hardware interface, a set of software commands, and a consistent set of data formats for point-to-point interconnection of medical equipment. However, it has been shown to be inadequate for PACS networking environments, because of its point-to-point nature and its inflexibility to allow other services and protocols in the future. Based on previous experience of PACS developments in The University of Arizona, a new communication protocol for PACS networks has been suggested to the ACR-NEMA Working Group VI. The defined PACS protocol is intended to facilitate the development of PACS's capable of interfacing with other hospital information systems. Also, it is intended to allow the creation of diagnostic information data bases which can be interrogated by a variety of distributed devices. A particularly important goal is to support communications in a multivendor environment. The new protocol specifications are defined primarily as a combination of the International Organization for Standardization / Open Systems Interconnection (ISO/OSI) protocols and the data format portion of ACR-NEMA standard. This paper addresses the specification and implementation of the proposed PACS protocol into network node. The protocol specification, which covers Presentation, Session, Transport, and Network layers, is summarized briefly. The implementation has natural extentions to Global PACS environments. The protocol implementation is discussed based on our implementation efforts in the UNIX Operating System Environment. At the same time, results of performance evaluation are presented to demonstrate the implementation of defined protocol. The testing of performance analysis is performed on the PACS prototype node.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.2
• /
• pp.86-89
• /
• 2018

This paper introduces a ZigBee network-based four-lane lap time measurement system that can be set up for short-distance races. The instructions "Ready-Set-Go" can be announced at the entry point node when the start button is pushed, and foot switches installed at the exit point node can be stepped on by the runner for lap time measurement of the race. The start and exit point nodes are connected to a ZigBee network to communicate time synchronization packets. The exit point node maintains synchronized local time within 10 ms at most. The system does not need expensive measurement equipment and provides lap time recording in a more convenient manner than conventional lap time measurement methods.

• Tunnel and Underground Space
• /
• v.8 no.3
• /
• pp.226-233
• /
• 1998

Microcracks in rock materials, whether natural or induced, provide useful information on the engineering performance of in situ rockmasses. A population of preferentially oriented microcracks has observable effects on the physical properties of a rockmass, but their effects may not be evident if the rock material is highly anisotropic due to other causes. An experimental program was undertaken to investigate the effect of rock fabrics on the physical properties of rock materials. In this study, anisotropy in the circumferential wave velocity and the direction of induced fractures under axial point loading were measured. Rock specimens (NX-size) of the leucocractic Pocheon granite were cored from rock blocks, retaining the relative directions of each specimen. Another set of specimens was prepared from the rock cores of the same meterial, obtained in the field. The master orientation line (MOL) was set to be the representative direction of the microcracks in the specimen. Variation of the circumferential wave velocity of each specimen was then measured along the core, keeping the MOL as reference. The direction of the minimum wave velocity was nearly perpendicular to the direction of the MOL. Coring of smaller-sized (EX-size), concentric specimens from the NX specimens were then followed, and axial point loading was applied. The direction of induced fractures due to axial point loading was closely related to the MOL direction, confirming the prior test result.

• Journal of KIISE:Computer Systems and Theory
• /
• v.29 no.2
• /
• pp.94-104
• /
• 2002

As a part of scientific data visualization automatic generation algorithms for a contour map have been investigated mainly on data which are defined at every lattice point. But in actual situation like weather data measurement. it is impossible to get data defined at every lattice point This is because the exact value on every lattice point can not be obtained due to characteristics in sampling devices or sampling methods. In order to define data on every lattice point where data were not sampled an interpolation method. was applied to the sample data to assign approximate values for some lattice type data but by using the non-lattice type of sample data sets. A triangle data link was defined by using non lattice points directly based on actually sample data set, not by using the pre-processed rectangle lattice points. The suggested algorithm generates a contour map a contour map only by using sample data set which are much smaller than old one without data interpolation and there is no skew on data any more since it does not need any interpolation to get the values of the defined lattice points.

• Journal of the Chungcheong Mathematical Society
• /
• v.26 no.4
• /
• pp.853-867
• /
• 2013

In this paper we study the cardinality of the dot product set generated by two subsets of vector spaces over finite fields. We notice that the results on the dot product problems for one set can be simply extended to two sets. Let E and F be subsets of the d-dimensional vector space $\mathbb{F}^d_q$ over a finite field $\mathbb{F}_q$ with q elements. As a new result, we prove that if E and F are subsets of the paraboloid and ${\mid}E{\parallel}F{\mid}{\geq}Cq^d$ for some large C > 1, then ${\mid}{\Pi}(E,F){\mid}{\geq}cq$ for some 0 < c < 1. In particular, we find a connection between the size of the dot product set and the number of lines through both the origin and a nonzero point in the given set E. As an application of this observation, we obtain more sharpened results on the generalized dot product set problems. The discrete Fourier analysis and geometrical observation play a crucial role in proving our results.

• Proceedings of the KIEE Conference
• /
• 2006.07a
• /
• pp.515-516
• /
• 2006

본 논문은 풍속이 변화하는 상황에서 풍력 발전 시스템의 동작을 실시간으로 모의할 수 있는 시뮬레이터의 구성과 실험 결과를 제시한다. 본 논문에서 제시하고자하는 풍력 발전 시스템 시뮬레이터는 실시간 시뮬레이터인 RTDS(Real Time Digital Simulator)와 11kW의 AC 서보 시스템을 포함하는 전동기-발전기 실험 장치(MG set, Motor-Generator Set)로 구현되었다. RTDS는 풍속 모델과 블레이드, 터빈, 발전기를 포함하는 풍력발전 시스템 모델을 실시간으로 모의하며 MG-set은 실시간으로 모의된 풍력 발전 시스템의 물리적 상태를 구현한다. 풍력 발전 시스템 모델의 동작점 궤적과 최대출력점추종(Maximum Power Point Tracking)제어에 의한 풍력 발전 시스템 시뮬레이터의 운전 결과의 제시를 통해 시뮬레이터의 유용성을 검증하였다. 본 논문에서 제시된 시뮬레이터는 상용 실시간 시뮬레이터를 이용하여 간단한 소프트웨어의 수정을 통해 다양한 모델의 풍력 반전 시스템을 모의할 수 있으며 다양한 실험 조건에서 과도상태 및 정상상태 특성 실험이 가능하므로 풍력 발전 시스템의 발전기 특성 평가, 전력 변환 장치의 성능 시험 등에 활용이 가능하다.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.12
• /
• pp.1267-1271
• /
• 2014

There have been many autonomous robot calibration methods which form closed loop structures through the various attached sensors and mechanical fixtures. Single point calibration among them has been used for on-site calibration due to its convenience of implementation. The robot can reach a single point with infinitely many configurations so that single point calibration algorithm can be set up and easily implemented relative to the other methods. However, it is not still easy to drive the robots' sharp edge to its corresponding edge of the fixture. This is error-prone process. In this paper, we propose a 3 dimensional small displacement measuring sensor and a robot calibration algorithm based on this sensor. This method relieves the difficulty of matching two edges in the single point calibration and improves the resulting robot accuracy. Simulated study is carried out on a Hyundai HA06 robot to show the effectiveness of the proposed method over the single point calibration. And also, the resulting robot accuracy is compared with that from 3D laser tracker based calibration to show the dependency of robot accuracy on range of the workspace where the measurement data are collected.

• Journal of Environmental Impact Assessment
• /
• v.16 no.6
• /
• pp.525-532
• /
• 2007

In order to establish and implement the total maximum daily load (TMDL) management plan in Korea, it is necessary to set the source units and calculate discharge loads for non-point source pollutants such as BOD, COD, SS, TN and TP. This study analysed the corelation between stormwater runoff characteristics and event mean concentrations (EMCs) of non-point source pollutants. As the result of the corelation analysis, we knew that all the antecedent dry days (ADD) and the rainfall correlated lowly with non-point source pollutants in the urban areas such as resident area, industrial area, business area, road area and parking area. Therefore, it is necessary to get all samples from stormwater starting point to stormwater ending point and standardize the sampling method of stormwater in order to obtain more accurate EMCs for landuse.