공기 중 음향 전송 시 부가 정보 삽입을 위한 오디오 워터마킹 기법

최준환(Joon Hwan Choi),송원석(Wonseok Song),최혁(Hyuk Choi),김태정(Taejeong Kim) 한국정보과학회 2010 정보과학회논문지 : 정보통신 Vol.37 No.2

오디오 워터마킹이란 오디오 신호에 귀에 들리지 않게 정보를 삽입하는 과정을 말하며, 주로 저작권 보호 목적에 이용되어 왔다. 본 연구에서는 오디오 워터마킹을 저작권 보호가 아닌 사용자 편의를 위한 부가 정보 전송이라는 목적에 이용하고자 하며, 이러한 목적에 적합한 오디오 워터마킹 알고리듬을 제안한다. 본 연구에서 제안하는 오디오 워터마킹 알고리듬은 공기 중 음향 전송을 통해 스피커로부터 모바일 장치로 부가 정보를 전송하는 방식이며, 오디오 신호의 에너지 변조를 이용한 워터마크 삽입/추출 방법 및 2단계에 걸친 효율적인 동기화 방법을 포함한다. 제안된 알고리듬은 스피커 시스템과 휴대폰 단말기를 이용한 실험을 통해 그 성능을 평가하였으며, 실험 결과 5m 거리에서 성공적으로 부가 정보를 전송이 가능함을 확인하였다. 이는 기존의 방식보다 높은 성능이다. Audio watermarking is the process of embedding inaudible information in an audio signal and has been widely used for copyright protection. In this research, we use the audio watermarking not for copyright protection but for the transmission of side information for user convenience, presenting an algorithm suitable for this purpose. Our new algorithm includes watermark embedding/extraction methods during acoustic transmission through the air that employ energy modulation of the audio signal and an efficient two-step synchronization method. The proposed algorithm is evaluated in experiments of conveying information from audio speakers to a mobile phone. The results show that reliable transmission is possible within a 5m range, which is an improvement achieved by our algorithm as compared to the existing one.

하드웨어 효율적인 동적 커패시턴스 보상 구현을 위한 고속 영상 압축 및 화소별 스위칭 기법

최준환(Joon Hwan Choi),송원석(Wonsuk Song),최혁(Hyuk Choi) 한국정보과학회 2009 정보과학회논문지 : 소프트웨어 및 응용 Vol.36 No.8

동적 커패시턴스 제어(DCC) 기술로 인하여 액정 디스플레이 장치의 약점 중 하나였던 응답시간 성능이 크게 개선되었다. 하지만 DCC는 계산 과정에서 이전 프레임 영상의 실시간 저장 및 출력을 반복해야 하며, 이 과정에 활용되는 고속 메모리는 HD 고해상도 디스플레이 제작에 있어 높은 하드웨어적 부담 및 비용 상승의 원인이 된다. 본 연구에서는 복잡도가 낮은 고속 영상 압축 기법인 변형 지수-골룸 (MEG) 코딩을 제안하며, 이를 통해 DCC 기술에 요구되는 메모리의 양을 크게 줄일 수 있다. 또한 본 연구에서는 화소별 DCC 스위칭 기법을 제안하여 압축 오차가 최종 액정 디스플레이 영상의 시각 품질에 악영향을 미치지 않도록 하였다. 제안된 방식을 이용해 DCC 처리용 메모리의 크기를 1/3로 줄여도 최종 영상의 시각 품질 손상이 거의 없음을 실험을 통해 확인할 수 있었다. Thanks to Dynamic Capacitance Control (DCC) technique, response time of an LCD display has greatly improved. However, DCC requires hi-speed memory for the real-time writing/reading of an image of a previous frame, which results in increases in hardware overhead and cost. In this paper, we propose Modified Exponential Golomb (MEG) coding, a low-complex high-speed image compression method, which can remarkably reduce memory requirement for DCC. We also propose a pixel-wise DCC switching technique to prevent a compression error from affecting the quality of a final image on LCD. In our experiment, the degradation in visual quality was not noticeable when we cut the DCC memory size of 1080i HD data by 1/3.

중국 전통 민간금융의 특징과 역할에 관한 연구 -민간 상호부조 조직인 합회(合會)를 중심으로-

최준환 ( Joon Hwan Choi ) 경남대학교 인문과학연구소 2013 人文論叢 Vol.31 No.-

중국 금융업의 특징은 이원금융체제이다. 정규금융과 비정규금융이 동시에 존재하고 있는 것으로, 비정규금융은 민간금융을 지칭한다. 중국의 민간금융 중 가장 오래되었으며 중요한 조직은 합회이다. 합회의 기원은 대략적으로 당송시대에 시작된 것으로 보고 있으며, 그 형성과 발전 과정에 있어 중국의 도덕체계와 가치 관념이 반영되고 있다. 중국의 전통사회는 농업을 중심으로 하던 사회였고, 지리적으로도 제한을 많이 받던 시기이기 때문에, 당시의 사람들은 혈연관계와 지연관계를 중시하였다. 따라서 이러한 관계에 의존한 안정적인 상호부조관계가 형성되었으며, 이러한 특수한 상황을 기초로 하여 형성된 금융조직이 합회이다. 합회의 근본적인 성격은 유지되고 있지만 경제가 발전하고 시간이 흐름에 따라 그 기능은 변천하였다. 가장 중요한 변화는 생활방면의 자금수요에서 생산방면의 자금수요로 변화하였으며, 참가 주체가 다양해졌고, 자금의 규모 역시 소액에서 거액으로, 금리 역시 저금리에서 고금리로 변화된 것이다. 특히 최근에는 민영 중소기업의 자금 조달 역할을 하면서 중국경제발전에 기여하고 있다는 것이다. China`s financial business structure characteristic is a two-tiered financial system. A two-tiered system means that regular and irregular finance exists at the same time. Irregular finance refers to informal finance. The oldest and most important of China`s informal finance organizations is He-Hui. The origin of He-Hui is reported to have started approximately during the Dang-Song dynasty. Its formation and process of development reflect China`s moral system and values. Chinese traditional society was centered on agriculture. At the time, people thought kinship and acquaintances were very important, because they had a lot of geographical limitations. Therefore, reliance on these relationships, stable mutual assistance was formed. The financial organization that formed on the basis of these special circumstances is He-Hui. He-Hui has maintained its fundamental nature, but, with economic development and the course of time, its function has changed. The most important changes are that capital demand of living area has changed to capital demand of production, and that the main agent of participation has been become diversification. The scale of funding has also changed from smaller amounts to huge funds, and the rate of interest has changed to higher interest rates from lower interest rates as well. Especially in recent years, He-Hui has served a role in financing small business administration, and it has contributed to the development of China`s economy.

중국 절강성 지역의 산업클러스터 연구

최준환 ( Joon Hwan Choi ) 한중사회과학학회 2014 한중사회과학연구 Vol.12 No.3

In this study, I mainly analyzed the development factors of industrial cluster which was presented by Brown(2000), about the success factors of the industrial clusters master plan which is enforced as part of the upgrading of industrial structure by China’s Zhejiang Provincial Government. The results are follows. First of all, There is Zhejiang University that has a strong of leading research institutes and because there is formed in the medium which is emphasis on network of scientific researchers and academic paradigm centered on Zhejiang University, it is based on the solid foundation of science. Secondly, industrial atmosphere was formed by commercial experience from the past which has been linked with kin, regionalism and responsible to an important role in the propagation of knowledge and innovative activities. Thirdly, mainly in private enterprises, the number of companies is increasing continuously and many enterprises including “Alibaba” establish a business so, company based for the cluster development has become stronger. Fourthly, sustained reduction in unemployment and an increase in the employment rate refer to creation of employment and pursue new urbanization for attractive residential environment. Zhejiang’s potential of spatial scalability is very high and The work whole of Zhejiang to be networked has been promoted. Finally, although R & D investment is constantly increasing, the progress of private banking legalization have not appeared yet and activities such as venture capital and business angels are also not enough.

논문 : 분말야금법에 의한 고분자전해질 연료전지 분리판용 저접촉저항 316L 스테인리스강 복합소재 제조

최준환 ( Joon Hwan Choi ),김명환 ( Myong Hwan Kim ),김용진 ( Yong Jin Kim ) 대한금속재료학회 ( 구 대한금속학회 ) 2008 대한금속·재료학회지 Vol.46 No.12

Metal matrix composite (MMC) materials having low electrical contact resistance based on 316L stainless steel (STS) matrix alloy with ZrB2 particles were fabricated for PEMFC (Polymer Electrolyte Membrane Fuel Cell) separator by powder metallurgy (PM). The effects of the boride particle addition into the matrix alloy on microstructure, surface morphology, and interfacial contact resistance (ICR) between the samples and gas diffusion layer (GDL) were investigated. Both conventional and PM 316L STS samples showed high ICR due to the existence of non-conductive passive film on the alloy surface. The addition of the boride particles, however, remarkably reduced ICR of the samples. SEM observation revealed that the boride particles were protruded out of the matrix surface and particle density existing on the surface increased with increasing the boride content, causing increase of the total contact area between the conductive particles and GDL. ICR of the samples also decreased with increasing the boride content resulted from the increased contact area.

중국 도시군의 유동인구 구조 분석

최준환 ( Choi Joon Hwan ) 한중사회과학학회 2018 한중사회과학연구 Vol.16 No.2

The floating population has been increasing in China due to rapid economic development and accelerating industrialization speed after the reform and opening of 1978. The floating population is the key agenda of China’s future population development and the main factor of transition in urban, rural, and local structures. Furthermore, the continuous increase in the floating population is creating a large and unprecedented metropolitan regions. The metropolitan regions appearing in China are the subject of new urbanization. They are the main overflowing population areas as well as the strategic growth point of China’s development in their future economic society. After considering the situation above, this study selected 19 metropolitan regions of China, divided them into 3 regions and analyzed the structure of their floating population. The results are as the followings. First, the floating population of China showed to center around the metropolitan regions. When analyzed by regions, the amount of influx of floating population showed to highly increase around Guojia metropolitan regions, which are the center of major cities, followed by Quyu metropolitan regions and Diqu metropolitan regions. Second, in the analysis results by educational background of the floating population, the low educated tended to move onto the non-city groups while the educated showed great amount of flow into the major metropolitan regions. Third, in the analysis results of the floating population by the state of marriage, the single and first marriage showed high flowing rates into the major cities while the divorced and bereavement tended to greatly flow into the non-city groups. Lastly, in the analysis results by different age, in ages between 15 to 49, the floating population to metropolitan regions showed higher rates compared to the floating population to non-city areas. However, in ages over 50, the gap of the floating population rates between Guojia metropolitan regions and areas with no city groups showed to decrease. As a result, although China is institutionally restricting the flow of its population, floating population is taking place in forms of irregular workers and under the name of Migrant workers. In other words, though it is impossible in China for population movement between the urban and rural areas to happen in system, floating population is actually occurring in reality. Therefore, this study can ease off arguments that consider Harris-Todaro model and Lewis model to be inappropriate in the case of China and become the evidence to the fact that these models can somewhat decipher the reality of China.

홍콩과 미국에 복수 상장된 중국기업 주식의 정보전이 효과

최준환(Joon Hwan Choi),허흥호(Heung Ho Heur) 한양대학교 아태지역연구센터 2007 중소연구 Vol.31 No.3

중국의 외국인 취업제도에 관한 연구

최정석 ( Choi Jung Seok ),최준환 ( Choi Joon Hwan ) 국민대학교 중국지식네트워크 2019 중국지식네트워크 Vol.14 No.-

본 연구에서는 한국인을 포함한 외국인이 중국으로 취업을 하는데 있어 가장 중요하다고 볼 수 있는 중국의 외국인 인력정책, 사회보장제도, 비자제도 등 3가지를 중심으로 살펴보았다. 분석결과를 토대로 시사점을 제시하면 다음과 같다. 첫째, 외국인 인력정책 측면에서 보면, 외국인 취업허가제도의 핵심은 중국에서 이미 취업했거나, 신규 취업하는 외국인을 외국인 고급인재(A), 외국인 전문인재(B), 외국인 일반인력(C) 등 3가지 유형으로 구분하여 기준에 따라 분류 관리함을 알 수 있었다. 둘째, 사회보장제도 측면에서 보면, 2013년 1월 16일부터 발효된 “한-중 사회보험협정”은 중국에서 일하는 한국인 근로자에 대해 사회보험료 이중부담을 면제해주기 위해 체결된 양자 간 조약으로 일하는 나라의 해당 사회보험 적용이 각각 28%, 3%가 면제되기 때문에, 과거 이중으로 부담된 비용을 경감할 수 있는 긍정적인 효과를 볼 수 있게 되었다. 셋째, 비자제도 측면에서 보면, ‘외국인 출입국 관리조례’에 따르면 기존의 비자유형에 기초하여 F비자는 F비자와 M비자(무역비자)로, L비자는 L비자, Q비자(가족방문비자), S비자(개인사무비자)로 분할했고, 해외 우수인재의 영입과 중국 지식산업의 발전을 위하여 R비자(인재비자)를 신설하여 보통비자의 유형을 기존 8가지에서 12가지로 확대하였다. In this study, we focused on the three most important factors for foreigners, including Koreans, to work in China, namely, China's foreigner manpower policy, social security system, and visa system. Based on the results of analysis, suggestions are as follows. First, from the viewpoint of foreigner manpower policy, the core of the foreigner work permit system is three types of foreigners who have already worked or newly employed in China, including foreign advanced manpower (A), foreign manpower manpower (B) Type, and classified according to the criteria. Second, in terms of social security systems, the "Korea-China Social Insurance Agreement", which came into force on January 16, 2013, is a bilateral treaty concluded to exempt the Korean workers in China from the double burden of social insurance premiums. Of their social insurance coverage is exempted by 28% and 3%, respectively, so that they can see the positive effect of reducing the cost burdened in the past. Third, in terms of the visa system, according to the 'Immigration Control Act for Foreigners', based on the existing visa type, the F visa is for F visa and M visa (trade visa), L visa is L visa, Q visa ), And S visa (personal office visa). In order to recruit talented foreign talent and to develop the Chinese knowledge industry, R visas were newly created, expanding the usual visa types from 12 to 12 types.

열화학적 방법에 의한 산소센서용 세리아 나노분말 합성

이동원,최준환,임태수,김용진,Lee Dong-Won,Choi Joon-Hwan,Lim Tae-Soo,Kim Yong-Jin 한국분말야금학회 2006 한국분말재료학회지 (KPMI) Vol.13 No.3

The nanostructured cerium oxide powders were synthesized by spray thermal decomposition process for the use as the raw materials of resistive oxygen sensor. The synthesis routes consisted of 1) spray drying of water based organic solution made from cerium nitrate hydrate ($Ce(NO_3){_3}6H_2O$) and 2) heat treatment of spray dried precursor powders at $400^{\circ}C$ in air atmosphere to remove the volatile components and identically to oxidize the cerium component. The produced powders have shown the loose structure agglomerated with extremely fine cerium oxide particles with about 15 nm and very high specific surface area ($110m^2/g$). The oxygen sensitivity, n ($Log{\propto}Log (P_{O2}/P^o)^{-n}$ and the response time, $t_{90}$ measured at $600^{\circ}C$ in the sample sintered at $1000^{\circ}C$, were about 0.25 and 3 seconds, respectively, which had much higher performances than those known in micron or $100{\sim}200nm$ sized sensors.

중국 철강산업의 정책추이 분석

최정석(CHOI JUNG SEOK),최준환(Choi, Joon Hwan) 한국중국문화학회 2022 中國學論叢 Vol.- No.73

2020년 시진핑 주석의 탄소중립 선언을 기점으로 탄소배출이 많은 석탄 및 철강산업은 모든 정책에서 우선순위로 주목을 받기 시작하였다. 이에 본 논문에서는 2020년을 기점으로 전후로 나누어 주요 철강산업정책을 문헌을 토대로 정리하고 분석하였다. 우선 2020년 이전의 철강산업정책의 주요흐름을 살펴보면, 중국 철강산업은 1996년 세계 조강생산량 1위를 차지한 이후, 양적으로는 급속한 성장을 이어오고 있지만, 기술수준은 국제 선진수준에 비해 질적으로 차이가 있기 때문에 향후 발전의 중점은 기술업그레이드와 구조조정에 둘 것을 강조하며 산업정책과 문건들을 반포하였다. 다만 고질적인 문제점들을 변화시키려고 했지만, 한계에 봉착하는 모습들을 보여 2015년 기존 수요측면에서의 구조조정이 아닌 공급측면에서의 구조조정인 공급측개혁을 실시한 것으로 보여진다. 다음으로 2020년 이후 발표된 철강산업정책 및 문건들을 보면, 지속적인 지방정부의 생산량 억제 및 노후된 생산시설 업그레이드, 친환경 등에 중점을 두고 시행하였다. 과거 중국정부가 제기한 철강산업의 구조조정 외에도 최근에는 스마트 철강 및 철강생산의 탄소배출감소 등 친환경 철강산업 발전을 위해 대내외적으로 강조하였다. 또한 철강제품의 고부가가치 상품생산을 통한 국제경쟁력을 제고하기 위해, 각 지방정부에서 노후된 생산시설 폐쇄 및 업그레이드 정책들을 추진 중이다. 중국 철강산업은 과거 중국경제 양적성장을 대표하는 산업에서 2021년 중국정부의 철강산업정책의 패러다임 변화로 인해 향후 질적성장을 대표하는 산업이 될지는 지켜봐야 되겠지만, 확실한 부분은 과거 탄소배출을 중시하지 않으며 중국경제 성장을 이끌어왔던 모습에서 앞으로는 우선적으로 철강생산량 감축을 통해 친환경적인 부분에서부터 변화가 올 것으로 판단된다. After President Xi Jinping announced in 2020 to achieve carbon neutrality, the coal and steel industries with high carbon emissions began to receive policy attention. Therefore, this article takes around 2020 as the starting point, and based on the literature, sorts out and analyzes the main policies of the steel industry. First of all, from the perspective of the mainstream of steel industry policy before 2020, China s steel industry has been ranking first in the world s crude steel output since 1996, and the number has continued to grow rapidly, but there is a qualitative gap between the technical level and the international advanced level. Therefore, the introduction of It also formulated industrial policies and documents, emphasizing that the focus of future development should be on technological upgrading and structural adjustment. However, they are trying to change long-standing problems, but they have reached the limit, so it seems that in 2015, supply-side reforms, supply-side structural adjustment, rather than the existing demand-side structural adjustment, were implemented. Secondly, judging from the steel industry policies and documents announced after 2020, the focus of implementation is that local governments continue to suppress production, upgrade and transform outdated production facilities, and be eco-friendly. In addition to the structural adjustment of the steel industry proposed by the Chinese government in the past, the recent focus at home and abroad has been on the development of an eco-friendly steel industry such as smart steel and carbon reduction in steel production. In addition, in order to improve international competitiveness by producing high value-added products of steel products, local governments are promoting policies to close and upgrade outdated production facilities. As the Chinese government s steel industry policy in 2021 undergoes a paradigm shift from an industry that represented quantitative growth in China s economy in the past, it remains to be seen whether China s steel industry will become an industry that represents qualitative growth in the future. From the perspective of driving economic growth, the changes will first come from the environmental protection part of the reduction in steel production. 2020年习近平主席宣布实现碳中和后,碳排放高的煤炭和钢铁行业开始受到政策的重视。 因此本文以2020年前后为切入点,以文献为基础,对钢铁行业的主要政策进行了梳理和分析。 首先,从2020年前钢铁产业政策的主流来看,中国钢铁工业自1996年位居世界粗钢产量第一以来,数量持续快速增长,但技术水平与国际先进水平有质的差距层面因此,出台了产业政策和文件,强调未来发展的重点应该放在技术升级和结构调整上。然而,他们试图改变长期存在的问题,但他们已经到了极限,所以似乎在2015年实施了供给侧改革,即供给侧结构调整,而不是现有的需求侧结构结构调整。 其次,从2020年以后公布的钢铁产业政策和文件来看,实施的重点是地方政府持续抑制生产、落后生产设施升级改造、生态友好。除了中国政府过去提出的钢铁行业结构调整外,近期国内外都将重点放在了智能钢铁和钢铁生产减碳等生态友好型钢铁行业的发展上。此外,为了通过生产钢铁产品的高附加值产品来提高国际竞争力,各地政府都在推动关闭和升级落后生产设施的政策。 由于2021年中国政府的&