• Journal of IKEEE
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• v.23 no.1
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• pp.14-21
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• 2019

In this paper, we implemented an on-board miniaturization antenna operating 2.4 GHz using MZR(Mu Zero Resonator). It is must be operating under the constraint that the size of the small terminal PCB should be $78{\times}38{\times}0.8mm^3$ and the size of the system should be $63{\times}38{\times}0.8mm^3$ and the size of the radiating part should be $15{\times}38{\times}0.8mm^3$. The feeding structure uses a CPW structure for stable feeding and a feeding point at the upper left of the system board. A magnetic field coupling structure is used for coupling the feeding part and the antenna. The resonance frequency of the MZR is determined by the series inductance and capacitance of the cell, so the gap between the cells, the length of the cell, the length of the interdigital capacitor, and the spacing between the radiation part and the ground plane are analyzed. The antenna was designed and fabricated using the results. The total size of the antenna including the feed structure is $20.8{\times}9.0{\times}0.8mm^3$, and the electrical length is $0.1664{\lambda}_0{\times}0.072{\lambda}_0{\times}0.0064{\lambda}_0$. The measurement result for 10 dB bandwidth, gain and directivity are 440 MHz(18.3%), 0.4405 dB, and 2.722 dB respectively. It is confirmed that the radiation pattern has omnidirectional characteristics and it can be applied to ultra small terminal antenna.

• Progress in Medical Physics
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• v.14 no.4
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• pp.218-224
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• 2003

Purpose：By evaluating the dependence of the tray transmission factor (tray factor) on collimator setting and tray thickness, we determined the validity of the clinically used single tray factor for standard radiation field size (10${\times}$10 $\textrm{cm}^2$). Methods and Materials：For each X ray energies (6 and 10 MV), outputs were measured by using 5 steps of tray thickness (0, 6, 8, 10, 12 mm) and 7 steps of radiation field size (5${\times}$5, 10${\times}$10, 15${\times}$15, 20${\times}$20, 25${\times}$25, 30${\times}$30, 35${\times}$35 $\textrm{cm}^2$) at 10 cm phantom depth. Outputs were measured in both 'with tray' and 'without tray' conditions by using radiation with the same monitor units, and the tray factors were determined by the ratios of the two outputs. To evaluate the validity of a single tray factor obtained for standard radiation field, we analyzed the pattern of the field sizes in cases treated at our hospital in 2002. Results : In the 6 MV X-ray, the increases in the tray factor between the standard field (l0${\times}$10 $\textrm{cm}^2$) and the largest field (35${\times}$35 $\textrm{cm}^2$) were 0.517%, 0.835%, 1.058%, 1.066% in 6, 8, 10, and 12 mm thickness tray, respectively. In the 10 MV X-ray, the increases in the fray factor between the standard field (10${\times}$10 $\textrm{cm}^2$) and the largest field (35${\times}$35 $\textrm{cm}^2$) were 0.517%, 0.836%, 1.058%, 1.066% in 6, 8, 10, 12 mm thickness tray, respectively. In a major portion of clinical cases, when the field size was smaller than 20${\times}$20 $\textrm{cm}^2$, the tray factor was in good agreement with the standard tray factor. However, in cases where the field sizes were 30${\times}$30 $\textrm{cm}^2$ and 35${\times}$35 $\textrm{cm}^2$, the error could exceed 1.0%. Conclusion：The tray factor increased with increasing field size or decreasing tray thickness. The difference of tray factor between the small field and the large field increased with increasing tray thickness. Furthermore, the standard tray factor was valid in most clinical cases except for when the field size was greater than 30${\times}$30 $\textrm{cm}^2$, wherein the error could exceed 1.0%.

• Annual Conference of KIPS
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• 2006.05a
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• pp.839-842
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• 2006

대부분의 불리언 행렬에 대한 연구는 두 불리언 행렬의 곱셈에 초점을 두고 있으며 모든 불리언 행렬을 대상으로 한 곱셈에 대한 연구는 최근에야 극히 소수의 연구결과가 보이고 있다. 이 연구들은 모든 불리언 행렬 사이의 곱셈 실행시간을 개선시켰으나 연속된 세 개의 모든 lxn, nxm, mxk 불리언 행렬에 대한 곱셈은 아직 많은 개선이 필요하다. 본 논문은 모든 $l{\times}n,\;n{\times}m,\;m{\times}k$ 불리언 행렬의 곱셈 실행시간을 보다 개선할 수 있는 이론을 제시하고 이를 적용한 불리언 행렬 연속곱셈의 실행결과에 대하여 논한다.

• Journal of applied mathematics & informatics
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• v.26 no.3_4
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• pp.471-479
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• 2008

Let $R\;{\in}\;C^{m{\times}m}$ and $S\;{\in}\;C^{n{\times}n}$ be nontrivial unitary involutions, i.e., $R^*\;=\;R\;=\;R^{-1}\;{\neq}\;I_m$ and $S^*\;=\;S\;=\;S^{-1}\;{\neq}\;I_m$. We say that $G\;{\in}\;C^{m{\times}n}$ is a generalized reflexive matrix if RGS = G. The set of all m ${\times}$ n generalized reflexive matrices is denoted by $GRC^{m{\times}n}$. In this paper, an efficient method for the least squares solution $X\;{\in}\;GRC^{m{\times}n}$ of the matrix equation AXB = D with arbitrary coefficient matrices $A\;{\in}\;C^{p{\times}m}$, $B\;{\in}\;C^{n{\times}q}$and the right-hand side $D\;{\in}\;C^{p{\times}q}$ is developed based on the canonical correlation decomposition(CCD) and, an explicit formula for the general solution is presented.

• Korean Management Science Review
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• v.31 no.2
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• pp.65-70
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• 2014

This paper considers a single machine scheduling problem to determine release and processing times where both the release times and processing times are linearly decreasing functions of resources. The objective is to minimize the sum of the associated resource consumption cost and scheduling cost including makespan, sum of completion times, maximum lateness, or sum of lateness. This paper proves that the scheduling problem is NP-hard in the strong sense even if the release times are constant.

• The Korean Journal of Emergency Medical Services
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• v.4 no.1
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• pp.57-61
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• 2000

This is a study to evaluate the effects of the change of EMT students' acceptance on meaning "Korean style translation of EMT". The major instruments of this study were Korean Self-Analysis Acceptance Opinionnaire. This Questionnaire contains 3 items which measure students' opinions or attitudes. The data were analyzed by the path analysis - with SPSS and AMOS package program. The result are as follows: 1) Y(before admission) ＝ $0.11{\times}1$(teaching)+$0.12{\times}2$(elder)+$0.57{\times}2$(peer)+E. 2) Y(student) ＝ $0.87{\times}1$(teaching)+$0.49{\times}2$(elder)+$0.59{\times}2$(peer)+E. 3) Y(before graduation) ＝ $0.57{\times}1$(teaching)+$0.63{\times}2$(elder)+$0.73{\times}2(peer)$+E.

• Journal of Information Technology Services
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• v.5 no.1
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• pp.191-198
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• 2006

Boolean matrices have been successfully used in various areas, and many researches have been performed on them. However, almost all the researches focus on the efficient multiplication of two boolean matrices and no research has been shown to deal with the multiplication of all boolean matrices and their consecutive multiplications. The paper suggests a mathematical theory that enables the efficient consecutive multiplications of all $l{\times}n,\;n{\times}m,\;and\;m{\times}k$ boolean matrices, and discusses its computational complexity and the execution results of the consecutive multiplication algorithm based on the theory.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.12
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• pp.1154-1160
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• 2005

A panoramic-PIV system has been constructed for the analysis of the airflows in a room. Smoke is used as seeding particles and are visualized by a pulsed laser (Nd-Yag, 120 mJ). Panoramic images have been obtained by an image composition process using the two images obtained by the two cameras $(1k\times1k)$ that are viewing the wide measurement areas. Velocity vector fields have been obtained by the grey-level cross-correlation PIV method. Three room models $(L{\times}W{\times}H[mm^3],\;500\times500\times250,\;350\times350\times175,\;250\times250\times125)$ have been tested. The experimental results have proven that the constructed panoramic-PIV system can be used as a useful tool for analyzing the airflow characteristics in the room models.

• Journal of the Korean Vacuum Society
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• v.2 no.4
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• pp.399-403
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• 1993

Si(111)7 $\times$ 7 위에 Mg를 흡착시켜 표면구조의 변화를 RHEED(Reflection High Energy Electron diffraction) 와 XPS(X-ray PhotoelectronSpectroscopy)를 이용하여 연구하였다. RT ~20$0^{\circ}C$까지의 기판온도에서 증착량의 증가에 따라 표면구조는 (7$\times$7)에서 diffused (1$\times$1) 그리고 (2 3 3 $\times$2√3√3-R30$^{\circ}$) 구조로 변화하였다. 또한, 기판온도를 증가시킴에 따라 (1$\times$1), three domain(3$\times$1) 등의 구조를 볼 수 있었고, 특히 , $450^{\circ}C$의 기판온도에서는 single domain (3$\times$1) 구조를 최초로 관측하였다. 이렇게 형성된 각 구조에 대한 Mg KLL과 Si2p의 XPS peak intensity ratio를 증착량의 증가에 따라 측정하여 각기 다른 온도에서의 Mg 성장에 대한 메카니즘을 제시하였다.

• Journal of Acupuncture Research
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• v.19 no.3
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• pp.168-179
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• 2002

Objective : To research the trend of the study related to electroacupuncture and to establish the hereafter direction for the study on electroacupuncture. Methods : We have referred to PubMed, with electroacupuncture (Limits: 5 Years, only items with abstracts, English, Human) Results : 1. We have searched 67 papers in 49 journals on electroacupuncture. 2. The pattern of study was as follows: review articles-8 papers in 8 journals, RCT articles-22 papers in 16 journals, meta-analysis-2 papers in 2 journals, and clinical trials-29 papers in 14 journals. 3. How frequently each Meridians was used for electroacupuncture in the searched papers was as follows: Large Intestine Meridian-14 times, Stomach Meridian-12 times, GallBladder Meridian-5 times, Governor Vessel-4 times, Conception Vessel-3 times, Pericardium Meridian-2 times, Triple Energizer Meridian-2 times, and Liver Meridian-2 times in that order. 4. The acupoints used in the searched papers were as follows: LI4-8 times, ST36, LI11, and GB34-3 times, GV20, LR3, and PC6-2 times in that order. 5. The diseases in the searched papers were as follows: pain, stroke, and others. Conclusion : More clinical data would be needed to prove the effects of electroacupuncture for better application.