http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
On the Secrecy Rate and Optimal Power Allocation for Artificial Noise Assisted MIMOME Channels
Yun, Sangseok,Im, Sanghun,Kim, Il-Min,Ha, Jeongseok IEEE 2018 IEEE Transactions on Vehicular Technology VT Vol.67 No.4
<P>This paper considers the artificial noise (AN) scheme, proposed by Goel and Negi for securing wireless communications over multiple-input multiple-output multiantenna eavesdropper (MIMOME) channels. In this paper, we develop a lower bound on the ergodic secrecy rate of the AN scheme and derive an analytic expression of the bound without assuming any asymptotes for system parameters. Thus, the derived bound explicitly elucidates how the system parameters exert influence on the secrecy rate in various cases to some of which the previous work cannot be applied. It will also be shown that the bound is tight over wide combinations of system parameters, and a normalized difference between the bound and secrecy rate vanishes with a growing number of antennas at the transmitter. The derived bound is analytically so amenable that it enables one to not only extend the results of the previous work but also explore untouched aspects of the AN scheme. The bound answers an intriguing question: When is the AN signal beneficial? Besides, it makes possible to study a new important system parameter called the minimum required transmit power for a certain target secrecy rate, which has never been touched before.</P>
Export Promotion Effect under Consideration of Endogeneity and Interaction of Export Insurance
Jeongseok Song,Yun-Mi Nam,Chang-Bong Kim 한국무역금융보험학회(구 한국무역보험학회) 2021 무역금융보험연구 Vol.22 No.5
본 논문은 수출보험의 수출촉진 효과를 고려함에 있어 수출보험과 수출 사이의 양방향 인과관 계로 인한 내생성 문제를 논의한다. 이를 위해 수출보험의 수출 기여도 추정에 있어 내생성 이슈를 고려하여, 수출대상 국가의 정치적, 제도적 안전성을 도구변수로 사용하고자 하였다. 본 연구는 국가의 정치적, 제도적 안전성을 나타내는 척도 중 하나인 정부효율성 수준을 수출 보험의 도구변수로 하는 고정효과 추정을 실시하였다. 이외에 수출 대상국가의 GDP, 투자, 환 율, 인구 등의 요인들이 수출보험의 수출 촉진효과에 어떠한 영향을 주는지를 알아보았다. 실증 분석 결과에 따르면, 수출보험은 한국의 수출 증대에 기여하며, 수출촉진 효과는 수출보 험과 수출 사이의 양방향 인과관계에 따른 착시효과가 아님을 증명하였다. 또한, 상호작용 효 과의 분석 결과 GDP규모가 큰 수출 대상 국가에 대한 수출보험의 수출촉진효과가 타 국가에 비해 큰 것을 확인하였으며, 수출보험의 긍정적 효과에 대한 시사점을 제공하였다. Purpose : This study investigates the issue of endogeneity due to the bidirectional causal relationship between export insurance and exports in considering the export promotion effect of export insurance, using instrument variables including the political and institutional safety of the export target country. Research design, data, methodology : The paper uses panel data from 160 countries and utilizes the panel data analysis based on a regression. Major variables in this study include export insurance, political and institutional safety, and other economic variables. This paper hypothesizes that export insurance would have a positive effect under the endogeneity and the interaction. Results : The results suggests that export insurance contributes to the increase of South Korea's export, and that the export promotion effect is not an illusion due to the two-way causal relationship between export insurance and exports. Conclusions : Coping with endogeneity for export insurance, this paper finds that export insurance contributed to South Korea's export growth. Considering the interaction effect of the export insurance and GDP, this paper shows that the export promotion effect of export insurance for export destination countries with larger GDP is greater than that of other countries.
윤미정(Mijung Yun),김미래(Mirae Kim),강건(Gun Kang),오정석(Jeongseok Oh),이성훈(Seonghoon Lee),나선채(Seongchae Na),이현종(Hyunjong Lee) 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11
Due to a growing interest in sustainability and control of raw material costs in all types of industrial production, use of Natural oil polyol has become more and more popular in the Polyurethane foam industry. This study describes work focused on replacing petroleum based polyols with castor based polyols in flexible foam application. As a result of development, we applied 10% biomass seat foam with based on castor oil.
( Dongsub Noh ),( Jeongseok Yun ),( Ye Rim Chang ) 대한외상학회 2020 大韓外傷學會誌 Vol.33 No.3
Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been increasingly used in recent years as a resuscitative adjunct for trauma patients with life-threatening non-compressible torso hemorrhage. By blocking the aorta temporarily with an inflated balloon, REBOA preserves cerebral and coronary perfusion while diminishing exsanguination below the balloon, thereby providing time for resuscitation and definitive bleeding control. When determining the occlusion zone during the REBOA procedure, factors such tortuosity of the aorta, co-occurring minor chest injuries, and the severity of shock must be considered, as well as the main injury site. This paper describes a case of high Zone I REBOA in an elderly patient with a tortuous aorta who had concomitant injuries of the chest and pelvis.