수소 연료 생산의 효율향상을 위한 초음파 응용에 관한 연구 - 압력센서 계기에 의한 -

송민근,손승우,주은선,Song, Min-Guen,Son, Seung-Woo,Ju, Eun-Sun 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.9

The production of hydrogen fuel depends basically on the water electrolysis. The ultrasonic effects the decrease of the overpotential in a water electrolysis. A study on the overpotential which activates the hydrogen production is the core to elevate the hydrogen production efficiency on the principle. A pressure sensor system by a new idea is developed and applied. Solutions are 4 kinds of KOH concentration such as 0%, 10%, 20%, and 30%. Two frequency bands of the ultrasonic transducer are 28kHz and 2MHz. The directions of ultrasonic forcing are the vertical direction and the horizontal direction. The temperatures are two states, i.e., no constant and constant. Experiments are carried out sequentially in order in three cases of no ultrasonic forcing, ultrasonic forcing, and ultrasonic discontinution. In results, it is clarified that the ultrasonic effects the decrease of overpotential to elevate the efficiency of hydrogen production.

사회네트워크분석을 이용한 인천경제자유구역(IFEZ) 입주대학의 중심구조 변화 분석

송민근(Min geun Song),이진규(Jin kyu Lee),전준우(Jun woo Jeon),여기태(Gi tae Yeo) 한국국제상학회 2015 國際商學 Vol.30 No.4

본 연구는 사회네트워크분석(SNA)을 활용하여 경제자유구역(IFEZ)에 입주한 대학의 중심구조 변화추이를 분석하고 그 결과를 통해 현재 추진 중인 정책 사업이 사회적으로 미치고 있는 영향을 파악하는데 그 목적을 두었다. 분석 대상은 세계대학순위 200위권 상당의 대학을 대상으로 하였으며 미국, 영국, 중국의 10위권 상당의 대학과 국내대학과의 교류네트워크 연결 중심성을 통해 네트워크 구조를 분석했다. 2008년 연세대학교의 연결 중심성은 1.000으로 나타났으나 2013년에는 10.000으로 나타나 해외 우수대학들과의 직접적 교류가 증가하고 있는 것으로 나타났다. 본 연구를 통해 살펴본 연도별 변화 추이와 사회네트워크 분석의 관점에서 현재 경제자유구역청이 추진하고 있는 인천글로벌대학 프로젝트는 한국의 글로벌 교육환경조성에 기여하고 있는 것으로 해석된다. Purpose : This paper aims to analyze the Network Centrality of the universities attracted in Incheon Free Economic Zone (IFEZ) in the network with world's top-ranked universities. Research design, data, methodology : We apply the Social Network Analysis(SNA) Methodology using the degree centrality. Subject of the analysis was the network among the world's top-ranked universities. Among the foreign universities, the top 10 universities in the United States, the top 7 universities in China, and the top 10 universities in the UK were included. Results : As for the result of the degree Centrality of Yonsei University which attracted IFEZ, the degree centrality as of 2008 is shown in 1.00, but the degree Centrality as of 2013 increased to 10.00, it was found that the international relationship with foreign universities had been increased gradually. Conclusion : We could examine and confirm that there has been some meaningful changes in the network between foreign and domestic universities. The result of analysis shows that Incheon Global University Campus(IGUC) project has positively contributed to the development of the global educational environment in IFEZ and Korea.

2-레벨 및 3레벨 동작의 조합을 통한 3-레벨 NPC 인버터의 중성점 전류 저감 기법

송민근(Min-Geun Song),이교범(Kyo-Beum Lee) 대한전기학회 2020 대한전기학회 학술대회 논문집 Vol.2020 No.7

승용연료전지 자동차용 블로워 케이스의 방사소음 저감을 위한 CAE 이용 구조변경에 관한 연구

송민근(Song, Min-Keun),이상권(Lee, Sang-Kwon),서상훈(Seo, Sang-Hoon) 한국소음진동공학회 2008 한국소음진동공학회 논문집 Vol.18 No.9

The blower which is installed in a FCEV(fuel cell electric vehicle) may cause noise due to misalignment and unbalance of mechanical components that rotate at high speed. One of the key points in efforts to minimize the noise radiation from a blower is the knowledge of the main radiating component and the relation between the surface vibration of a blower and the sound pressure. In this research, the blower model is developed based on FEM(finite element method). FE(finite element) model is reliable by correlation of frequencies and MAC(modal assurance criterion) values between EMA(experimental modal analysis) and FEA(finite element analysis). This model is applied to predict the vibration of a blower by using inverse force identification method and predict the radiating noise by using BEM(boundary element method). Comparing the frequencies of resonance and those mode shapes between EMA and FEA, a structural modification of the FE model is evaluated for reducing the parameters of the blower noise.

RL 부하 연동 3상 태양광 발전 시스템의 부하 전류 센서리스 무효 전류 보상기법

송민근(Min-Geun Song),이우철(Woo-Cheol Lee) 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.7

CAE를 이용한 파워트레인의 방사소음 저감을 위한 구조변경

송민근(Minkeun Song),이상권(Sangkwon Lee),오기석(Kiseok Oh) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

One of the key elements in efforts to minimize noise radiation from a powertrain is the knowledge of the main radiating component and the relation between the surface vibration of a powertrain and the sound pressure. In this research, the powertrain model is developed based on FEM (finite element method). This model is applied to predict the vibration of a powertrain by using ADAMS and the radiation noise by using BEM (boundary element method). According to this numerical analysis, the surface vibration of a powertrain is investigated as a source of radiated noise. This surface vibration is caused by the Ist order natural vibration of the cylinder block and its mode shape is the torsion mode. Therefore, this mode shape is modified to reduce the surface vibration of the powertrain. The radiation noise of the modified powertrain is also reduced to 5~12㏈. This modification is very successful for the noise reduction based on the CAE technology.

태양광 발전 시스템의 120Hz 리플 전압 영향 감소를 통한 DC-Link 소형화와 출력 전류 왜곡률 감소에 관한 연구

송민근(Min-Geun Song),이우철(Woo-Cheol Lee) 전력전자학회 2021 전력전자학회 논문지 Vol.26 No.5

실내수조에서 그물코 규격에 따른 낙지(Octopus minor) 통발의 어획 성능

송민근(Min Geun SONG),이석구(Seokgu LEE),정재은(Jae-Eun JUNG),장윤호(Yun-Ho JANG),권인영(Inyeong KWON),김태호(Taeho KIM) 전남대학교 어업기술연구소 2019 어업기술연구소보고지 Vol.12 No.1

The objective of this study is to evaluate the catching efficiency of cylindric traps for common octopus, Octopus minor by mesh sizes and investigate the behavior patterns of common octopus in indoor water tank. A series of experiments were conducted in a recirculation aquaculture system with dimensions of 2100×1000×1100 mm. Observations of video camera footage were made of common octopus (Octopus minor) given the selection of experimental traps with different mesh sizes (18, 20, and 22 mm). Thirty common octopuses (wet weight 159.74±49.42 g; mantle length 73.43±18.77 mm) were used for each experiment. The experiments were replicated 3 times. The numbers of the animals entered by different mesh sizes were observed and recorded. The data were evaluated by an analysis of variance (ANOVA). More common octopuses were entered into traps with mesh sizes of 18-20 mm than 22 mm (P<0.05). It was observed that the common octopus was not aware of mesh sizes of traps in approaching and entering into the trap. The common octopus continued to search inside and outside of traps and entered into the trap by visual confirmation and olfactory stimulation.

2-유체 분무노즐의 초음파 적용에 관한 연구

송민근(Mingeun Song),이경렬(Kyungyoul Lee),나우정(WooJung La),주은선(Eunsun Ju) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.5

Characteristics of the twin fluid spray with ultrasonic forcing are examined in order to obtain the high efficiency of cold fog spray of the automatic pest control machine which has been widely used for the equipment cultivation recently.<br/> An electrostrictive vibrator of PZT BLT and a magnetostrictive vibrator of π type with 28kHz are<br/> applied as the ultrasonic transducer. All experiments are made and observed in 4 methods of spray ; a conventional spray method without ultrasonic forcing, an indirect vibration method with ultrasonic forcing. an improving quality method by ultrasonic forced within liquid. and a combined use method with both of the indirect vibration method and the improving quality method. In results, It was clarified that the ultrasonic effects the atomization of spray droplets and especially much more in the case of the combined use method.

키워드네트워크 분석을 활용한 중국 일대일로(OBOR) 사업에 관한 연구동향 분석

송민근 ( Min Geun Song ),차영두 ( Young Doo Cha ),여기태 ( Gi Tae Yeo ) 한국해운물류학회(구 한국해운학회) 2016 해운물류연구 Vol.32 No.2

본 연구는 SNA(Social Network Analysis)를 이용하여 중국 일대일로 사업의 연구 동향을 파악하는 것을 목적으로 하였다. 분석은 중국과 한국의 일대일로 연구 논문을 대상으로 했으며 중국 341개, 한국 73개 논문의 키워드를 통해 네트워크를 구성했다. 분석 결과, 공통적으로 OBOR, Trade, Cooperation 등이 높은 빈도를 보였고, 한국에서는 Eurasia Initiative에서 높은 빈도가 확인되었다. 연결 중심성에서 Strategy, China, Cooperation, Development, Trade, International, Logistics등이 높은 순위를 보였으며, 매개 중심성도 연결중심성과 큰 차이를 보이지 않았지만 한국 네트워크에선 AIIB, Eurasia 등이 상대적으로 높게 나타났다. 또한, 개별단어 네트워크를 구성하여 러시아, 인도, 미국 등 주요국가의 관련 키워드를 도출했으며, 한국이 중국과 대비하여 개별국가 및 지역에 대한 연구가 부족한 것을 확인할 수 있었다. The Chinese government has expressed commitment toward the "One Belt, One Road" (OBOR) project, which aims to construct large-scale logistics infrastructure across an extensive region spanning Central, West, and South Asia; the Persian Gulf; the Mediterranean Sea; the Indian Ocean; Europe; and the South Pacific. Additionally, the OBOR project activities between China and other major countries are already underway. In South Korea, the OBOR project has been drawing increasing attention of the central government, local governments, and major research institutes such as those pertaining to logistics (shipping, transportation), economy, trade, politics, diplomacy, culture and so on. As OBOR would be conducted by China and several other countries, there could be diverse viewpoints highlighting the "positives," "negatives," "opportunities," and "threats" of the project. Every single country associated with the OBOR project would have its own interpretation and approach. The correspondence strategies and projects derived from every single country would together constitute the OBOR project. To understand the project properly and find out the best way to cooperate, cope with, and utilize, there is a need for continuous and patient research. The research should be focused not only on the general understanding of OBOR but also on its specific projects in major countries. The purpose of this study is to identify the research trend regarding the OBOR project using SNA (social network analysis). The analysis was conducted by reviewing OBOR-related research papers published in China and South Korea as of April 2016. A total of 2,046 and 335 keywords were derived from the total keywords presented in 341 papers of China and 73 papers of Korea, respectively, for constructing a keyword network. Frequency analyses demonstrated that words such as "OBOR," "trade," and "cooperation" showed high frequencies in both China and Korea, while "Eurasia initiative" showed a high frequency in the Korean papers. In addition, in terms of network connection centrality, "strategy," "China," "cooperation," "development," "trade," "international," and "logistics" ranked high in both China and Korea. Although the difference between connection centrality and mediation centrality was not much, some mediation centrality keywords such as "AIIB" (which stands for Asian Infrastructure Investment Bank) and "Eurasia" had relatively high frequencies in Korea. Analysis on close centrality demonstrated that the Chinese papers showed significant values for "capital account liberalization," "business ethics," and "lone wolf." In addition, individual word networks were constructed with country names to derive keywords related to major countries, such as Russia, Mongolia, Pakistan, India, Vietnam and the United States. Compared to China, South Korea had relatively insufficient studies regarding individual countries and regions.