미국의 저위력 핵전력: 억제논리와 전망

김선홍,이만석 한국국방연구원 2024 국방정책연구 Vol.40 No.2

본 연구는 미국의 저위력 핵전력을 강화하는 전략적 동기와 억제 효과를 분석하며, 앞으로 저위력 핵무기와 관련된 미국의 정책을 예측한다. 이를 위해 본 연구는 저위력 핵전력 강화에 대해 미국 행정부가 제시하는 논리를 추적하고, 이것이 타당한지 게임이론과 수학적 모델을 활용하여 검증한다. 이러한 분석이 중요한 이유는 미국의 정부 공식문서나 저위력 핵무기 강화 배경에 관한 연구에서 저위력 핵전력이 억제력을 강화할 것이라고 주장하지만, 실제로 어떻게 억제력이 강화되는지 그 메커니즘을 명확히 제시하지 않기 때문이다. 이를 통해 미국의 저위력 핵무기 증강이 가지는 의미를 명확히 밝히고자 한다. 마지막으로 본 논문은 이러한 이해를 바탕으로 각 지역에서의 미국의 핵정책이 어떻게 전개될지에 대한 예측을 제시한다. This study examines the strategic motivations and deterrence effects behind the US' enhancement of low-yield nuclear forces and offers predictions for future U.S. nuclear policies. By tracing the logic presented by U.S. administrations and validating it through game theory and mathematical models, this study aims to provide a comprehensive analysis of this strategic move. This analysis is significant because, while U.S. government documents and studies often claim that low-yield nuclear forces will enhance deterrence, they rarely clarify the specific mechanisms through which this enhancement occurs. By addressing this gap. Finally, based on these insights, the paper forecasts how U.S. nuclear policy might evolve across different regions.

고전단 압출성형으로 인한 PC/ABS 블렌드의 열적 변화 연구

김선홍,이형일,김아라,유재정,용다경,이승구,이기윤,최석진,이한기 한국고분자학회 2013 한국고분자학회 학술대회 연구논문 초록집 Vol.2013 No.4

The zeros of certain family of self-reciprocal polynomials

김선홍 대한수학회 2007 대한수학회보 Vol.44 No.3

For integral self-reciprocal polynomialsP(z) and Q(z) withall zeros lying on the unit circle, does there exist integral self-reciprocalpolynomial Gr(z) depending on r such that for any r, 0 r 1, all zerosof Gr(z) lie on the unit circle and G0(z) = P(z), G1(z) = Q(z)? Westudy this question by providing examples. An example answers someinteresting questions. Another example relates to the study of convexcombination of two polynomials. From this example, we deduce the studyof the sum of certain two products of nite geometric series.

Representation of some binomial coefficients by polynomials

김선홍 대한수학회 2007 대한수학회보 Vol.44 No.4

The unique positive zero of Fm (z) := z2m zm +1 zm 1 1 leads to analogues of 22nk(k even) by using hypergeometric func-tions. The minimal polynomials of these analogues are related to Cheby-shev polynomials, and the minimal polynomial of an analogue of 22nk(k even > 2) can be computed by using an analogue of 22n2. In this pa-per we show that the analogue of 22n2is the only real zero of its minimalpolynomial, and has a dierent representation, by using a polynomial ofsmaller degree than Fm (z).

On self-reciprocal polynomials at a point on the unit circle

김선홍 대한수학회 2009 대한수학회보 Vol.46 No.6

Given two integral self-reciprocal polynomials having the sa\-me modulus at a point z_0 on the unit circle, we show that the minimal polynomial of z_0 is also self-reciprocal and it divides an explicit integral self-reciprocal polynomial. Moreover, for any two integral self-reciprocal polynomials, we give a sufficient condition for the existence of a point z_0 on the unit circle such that the two polynomials have the same modulus at z_0. Given two integral self-reciprocal polynomials having the sa\-me modulus at a point z_0 on the unit circle, we show that the minimal polynomial of z_0 is also self-reciprocal and it divides an explicit integral self-reciprocal polynomial. Moreover, for any two integral self-reciprocal polynomials, we give a sufficient condition for the existence of a point z_0 on the unit circle such that the two polynomials have the same modulus at z_0.

프리폴리머 조성에 따른 폴리우레탄 탄성체의 반응성 및 기계적 물성 연구

김선홍,이기윤 한국고분자학회 2014 한국고분자학회 학술대회 연구논문 초록집 Vol.2014 No.4

무형문화의 이주, 전승 그리고 음악적 변화 양상: 은율탈춤의 사례

김선홍 한국공연문화학회 2019 공연문화연구 Vol.0 No.39

In the paper, this study will be explored in the migration of the mask dance Eunyeul Talchum from North Korea to South Korea after the national division took place. During and after the Korean War, refugees from the Hwanghae province settled in the Republic of Korea who were performers of the three Korean mask dances: Bongsan Talchum, Kangryeong Talchum and Eunyeul Talchum. All of these mask dances are denoted as South Korea’s National Intangible Properties under the Cultural Property Protection Law (1962.) However, Eunyeul Talchum is the only asset among these three that settled in Incheon, instead of the capital, Seoul. The purpose of this research is to examine the process of restoring and the idea of transmitting Eunyeul Talchum in Incheon after the division of Korea. As opposed to Bongsan Talchum and Gangryeong Talchum, which are recognized as major socio-ethnic groups, Eunyeul Talchum belongs to a minority. Because not only Eunyeul Talchum is the last Mask Dance which has been nominated as an Intangible asset among the other Hwanghae Talchum but also, most people in the preservation association are comprised of the second-generation refugees from Hwanghae province. During three months of research, the researcher observed the performances and the educational communicating Eunyeul Talchum’s cultural legacy. This study included several research methods: open interview, examination of relevant documents, and live performances. Particularly, the researcher conducted interviews with the Human Cultural Property and musicians (including professional/scholarly to lay/untrained) in the Preservation Association. In conclusion, Eunyeul Talchum preservation association is not as preeminent as other Korean mask dances, it has been transmitted by performers from Hwanghae province with its unique masks and instrumental accompaniment. These performers and educators dedication to maintaining Eunyeul Talchum’s attributes contribute largely to the Preservation Association’s successful settlement in Incheon. Thus, the researcher examines which idea formed to subsist the Eunyeul Talchum preservation association. 1945년 광복 이후 남한과 북한이 분단된 상황 속에서 남한은 무형문화의 손실을 예방하기 위해 1962년 무형문화재 제도를 제정하면서 무형문화들을 발굴하고 복원하였다. 이 때 민속 문화를 포함한 여러 무형문화들이 무형문화재로 지정되었다. 국가 무형문화재로 지정된 민속 문화 중 북한에서 연행되었던 탈춤인 은율탈춤의 사례를 통해 무형문화재 제도 속에서 지정된 무형문화의 전승이 이루어진 과정과 반주음악의 변화 양상에 대해 다룬다. 음악적인 전승을 이루는데 보존회 중심의 구성원들이 국가무형문화재라는 틀 안에서 은율탈춤을 예술로 인식함으로써 그들의 이념과 정체성이 표상된다. 이로써, 제도 속에서 음악적인 전승을 이루는데 구성원들의 정체성과 이념은 불가분의의 관계임을 알 수 있으며 국가무형문화재의 구성 속에서 무형문화를 현재까지 지속시킬 수 있었던 과정을 살펴본다.

Integrated dynamics modeling for supercavitating vehicle systems

김선홍,김낙완 대한조선학회 2015 International Journal of Naval Architecture and Oc Vol.7 No.2

We have performed integrated dynamics modeling for a supercavitating vehicle. A 6-DOF equation of motion was constructed by defining the forces and moments acting on the supercavitating body surface that contacted water. The wetted area was obtained by calculating the cavity size and axis. Cavity dynamics were determined to obtain the cavity profile for calculating the wetted area. Subsequently, the forces and moments acting on each wetted part-the cavitator, fins, and vehicle body-were obtained by physical modeling. The planing force-the interaction force between the vehicle transom and cavity wall-was calculated using the apparent mass of the immersed vehicle transom. We integrated each model and constructed an equation of motion for the supercavitating system. We performed numerical simulations using the integrated dynamics model to analyze the characteristics of the supercavitating system and validate the modeling completeness. Our research enables the design of high-quality controllers and optimal supercavitating systems.

Alloying Effect of Copper on the Corrosion Properties of Low-Alloy Steel for Flue Gas Desulfurization System

김선홍,박선아,김정구,신기삼,Yinsheng He 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.2

The alloying effect of Cu for a flue gas desulfurization materials was investigated using the electrochemical methods in the modified green death solution and the surface analyses. The test results demonstrated that the densely formed rust layer with high metallic Cu content improves the corrosion resistance of Cu-containing steel in the flue gas desulfurization (FGD) environment. The rust layer on the surface of the 0.02 wt% Cu steel, which has an insufficient Cu content, was less protective than others. The 0.05 wt% Cu steel represented the highest corrosion resistance due to the formation of the densely formed rust layer with optimum Cu content. Because the free standing Cu2S precipitates had the insoluble characteristic in highly acidic solution, it produced the relatively porous Cu-enriched layer on the 0.08 wt% Cu steel surface. From these phenomena, the corrosion resistance of specimen decreased as the Cu content of specimen increased from 0.05 wt% to 0.08 wt%.

모바일 매니퓰레이터의 NMPC 기반 장애물 회피 및 전신 모션 플래닝

김선홍,Sathya Ajay,Swevers Jan,최영진 한국로봇학회 2022 로봇학회 논문지 Vol.17 No.3

This study presents a nonlinear model predictive control (NMPC)-based obstacle avoidance and whole-body motion planning method for the mobile manipulators. For the whole-body motion control, the mobile manipulator with an omnidirectional mobile base was modeled as a nine degreesof-freedom (DoFs) serial open chain with the PPR (base) plus 6R (arm) joints, and a swept sphere volume (SSV) was applied to define a convex hull for collision avoidance. The proposed receding horizon control scheme can generate a trajectory to track the end-effector pose while avoiding the self-collision and obstacle in the task space. The proposed method could be calculated using an interior-point (IP) method solver with 100[ms] sampling time and ten samples of horizon size, and the validation of the method was conducted in the environment of Pybullet simulation.