Dispersion studies of zirconia nanoparticles using cationic and anionic dispersants

조충희,조성근,함동석,이기윤,이재흥 한국고분자학회 2016 한국고분자학회 학술대회 연구논문 초록집 Vol.41 No.1

대용량 멀티포트 동시 충전 기반 수소충전소 안전성 평가 연구

조충희,강승규,김부승,이경식 한국수소및신에너지학회 2023 한국수소 및 신에너지학회논문집 Vol.34 No.5

Hydrogen infrastructure is expanding. High-capacity hydrogen refueling stations offer advantages because they can refuel a variety of light and heavy-duty vehicles, and multi-port refueling technology is developing to reduce charging time for heavy-duty vehicles. In this study, we suggest directions to lower the risk by analyzing the risk factors for each process involved in the installation of a high-capacity multi-port hydrogen refueling station in Changwon city. We conducted both qualitative and quantitative risk assessments of the equipment to evaluate the station. A hazard and operability study was performed for qualitative risk assessment, and PHAST/SAFETI were used for quantitative risk assessment. Quantitative risk assessment was used to calculate the consequence analysis of the facility to ensure secure design prior to station development and to predict individual and societal risks in various scenarios. As a result,

[눈물로 쓴 탈북민 수기] 출신과 차별, 그리고 선택

조충희 북한연구소 2017 北韓 Vol.- No.546

양극산화된 알루미늄 합금의 캐비테이션 특성에 미치는 봉공처리 효과

조충희,박일초,김성종 한국표면공학회 2016 한국표면공학회 학술발표회 초록집 Vol.2016 No.5

[특집] 북한의 축산업과 주민의 삶의 질

조충희 북한연구소 2023 北韓 Vol.- No.620

염기처리시간에 따른 지르코니아 현탁액의 분산성과 굴절율 변화

조충희,함동석,이재흥,류주환,이기윤,조성근,Jo, Choong Hee,Ham, Dong Seok,Lee, Jae Heung,Ryu, Juwhan,Lee, Kee-Yoon,Cho, Seong Keun 한국재료학회 2017 한국재료학회지 Vol.27 No.1

Zirconia nanoparticles were widely used as filler in order to get high refractive index layer. However, dispersion of nanoparticles is difficult due to their agglomeration in solvent. In this study, the dispersibility of the zirconia suspension is promoted by controlling the steric hindrance and electrostatic interactions through the adsorption of PEI according to alkali treatment time. Also, to induce improved dispersibility on suspension, we changed the dispersion conditions variously and fabricated an ink formulation method for the coating layer. Zirconia suspension was characterized by dynamic light scattering (DLS), Zeta potential measurement, Transmission Electron Microscope (TEM) and FT-IR. We were able to confirm that good dispersion of zirconia suspension by alkali treatment and PEI led to high refractive index.

양계산업 현황 및 미래 발전방안 - 북한 양계산업 현황 및 추진계획

조충희,Jo, Chung-Hui 대한양계협회 2018 월간 양계 Vol.50 No.11

북한지역에서 ASF발병 현황 및 남북수의협력에 관한 연구

조충희 적정기술학회 2020 적정기술학회지(Journal of Appropriate Technology) Vol.6 No.1

The ASF, which originated in Africa and threatens the world, landed in Asia in 2018 in China, and became a stern threat to the security of the Korean Peninsula when North Korea officially reported the ASF to the OIE in May 2019. In 1921, Montgomery, a British veterinary pathologist, made headlines by naming the African swine fever “African Swine Fever,” or ASF, a disease caused by a high fatality virus that existed in East Africa. The ASF, which was a pandemic of endemic diseases in Africa, landed in Portgal around 1957 and swept through farms in Lisbon, Portugal. The ASF continued to settle in Spain and Portugal, causing 40 years of damage until the end of the 1990s, and is now in progress after landing on the Italian island of Sardinia in 1978. The virus, which landed in Portiport of Georgia on the Black Sea coast of the Black Sea in 2007, spread to Russia and caused massive damage to China in 2018, then rapidly spread to Vietnam, Laos and Myanmar in May 2019 and spread across the country, causing massive damage to the pork industry and is now in progress. Just three months after confirming the outbreak in North Korea, the outbreak at farms in Paju and Yeoncheon was confirmed on Sept. 16, 2019, leaving South Korea with the stigma of ASF-causing countries, and although the ASF's nationwide expansion has been blocked, it is currently underway in wild boars. If the ongoing ASF in the two Koreas becomes indigenous, it would be a major disaster not only for the pork industry but also for the Korean Peninsula economy. Under the current circumstances, it is impossible to focus only on veterinary areas limited to South Korea, ruling out risk factors from the ASF outbreak. Currently, it is difficult to prevent damage to the pork industry due to the ASF outbreak due to the poor water defense reality in North Korea, and as it is adjacent to China, which has a high risk of developing various epidemic diseases, there is a need for the two Koreas to jointly conduct quarantine and quarantine on the border areas. First of all, I think rapid exchange of information and education on ASF and other diseases is necessary before establishing a joint defense system on the Korean Peninsula. It is important to conduct thorough quarantine and disinfection of ASF-generated areas in North Korea, and areas bordering China and Russia, and jointly conduct thorough quarantine and control of livestock and livestock products in circulation. Cooperation by the South and North Korean water defense industries to prevent the protracted ASF on the Korean Peninsula by all means and methods is essential. 아프리카에서 시작돼 전 세계를 위협하는 ASF는 2018년 중국지역에서 발생해 아시아에 상륙하였고 2019년 5월 북한이 OIE에 ASF를 정식신고 함으로써 한반도 축산안보에 엄중한 위협으로 되었다. 1921년 영국의 수의병리학자 몽고메리는 동아프리카에서 풍토병으로 존재하던 치사율이 높은 바이러스에 의한 열성 돼지열병에 ‘아프리카돼지열병African swine fever(ASF),’이라는 이름을 달아 세상에 알렸다. 아프리카지역에서 풍토병으로 유행하던 ASF는 1957년경 포르트갈에 상륙하여 포르투갈 리스본의 농장을 휩쓸었다. ASF는 계속하여 스페인과 포르투갈에 정착하여 1990년대 말까지 40년 동안 피해를 주었으며, 1978년에 이탈리아의 사르디니아섬에 상륙하여 현재진행형이다. 2007년에 흑해 연안의 죠지아 공화국의 포티항구에 상륙한 바이러스는 러시아까지 퍼졌고, 2018년에 중국에 침입하여 막대한 피해를 주면서 베트남, 라오스, 미얀마 등지로 급속히 퍼지다가 2019년 5월 북한에서 발병하여 전국에 확산되어 양돈업계에 막대한 피해를 주었으며 현재 진행형이다. 북한에서의 발병사실 확인후 불과 3개월 만에 2019년 9월 16일 파주와 연천의 농가에서 발병이 확인되면서 한국도 ASF발병국의 오명을 가지게 되었으며 ASF의 전국확산은 막았지만 야생 멧돼지에서 현재 진행형이다. 남북한에서 현재 진행중인 ASF가 토착화된다면 양돈산업은 물론 한반도 경제에 막대한 피해를 주는 역대 급 재앙으로 될 것이다. 현재의 상황상 ASF 발병으로 인한 위험요인을 배제하고, 남한지역에국한된 수의방역에만 치중할 수 없다. 현재 북한의 열악한 수의방역현실로는 ASF발생으로 인한 양돈업계의 피해를 방지하기 어렵고, 지리적으로 각종 유행성 전염병의 발병위험이 높은 중국과 인접되어 있어 국경지역에 대한 검역과 방역을 남북한이 공동으로 진행하여야 할 필요성이 제기된다. 우선 한반도공동방역체계를 구축하기전 과제로 ASF 및 기타 질병에 대한 신속한 정보교류와 교육이 필요하다고 생각한다. 북한의 ASF발생지역 및 중국, 러시아 접경지역에 대한 철저한 방역과 소독을 실시하고 유통되는 가축 및 축산물에 대한 철저한 검역과 통제 등을 공동으로 진행하는 것이 중요하다. 모든 수단과 방법을 동원하여 한반도에서 ASF의 장기화를 막아 한반도 축산안보를 보장하기 위한 남북한 수의방역업계의 협력이 필수적이다.

리눅스 커널의 가상 인터페이스 및 하드웨어 오프로딩에 관한 연구

조충희 한국지식정보기술학회 2022 한국지식정보기술학회 논문지 Vol.17 No.2

Recently, many companies that provide cloud services are emerging. Most companies configure their servers based on Linux to build a resource-efficient infrastructure to provide cloud services. Linux is an open source operating system close to a standard that has been developed with the participation and review of many developers over a long period of time. Linux virtualizes the resources required for the cloud, enabling efficient resource management. In addition, Linux supports networking performance improvement by offloading kernel functions to the network interface card. With the latest kernel, we can use the virtual interface and offload function of Linux. However, we find problems that do not work harmoniously between virtual interfaces and offload functions. This paper specifically analyzes the kernel code of MACsec which is is an IEEE Media Access Control security standard. We presents various problems that may occur when the MACsec virtual interface and the Bond virtual interface are used together. In addition, we also present a problem that network processing performance may be degraded due to receive side scaling when the network interface card processes encrypted packets. These issues disclosed in this paper can be expected to consider various compatibility issues when Linux code is provided as a cloud infrastructure in the future.

강화 학습을 통한 저비용 및 고가용성 네트워크 설계

조충희 한국지식정보기술학회 2022 한국지식정보기술학회 논문지 Vol.17 No.3

Telecommunication disasters have been regarded as national disasters that cause social chaos and economic losses in various fields such as medical care, emergency relief, public safety, finance, and commerce. Such disasters can be prevented by considering network availability during network design. However, telecommunication companies build networks with more focus on reducing construction costs than providing sufficient network availability. Network construction costs can be minimized if the network of other telecommunication companies are utilized without requiring the construction of 쟮ew protection paths to avoid traffic failure. Although most telecommunication companies have built their communication networks in geographically similar locations, they do not share networks despite the fact that shared networks could lead to improved network availability and reduced construction costs. Therefore, in this study, its introduced a method to minimize the network construction costs while improving the overall network availability. We defined an optimization problem to determine the optimal set of cable lines that can interconnect the networks and used a deep reinforcement learning algorithm to select the cable lines. The deep reinforcement learning algorithm learns to select the optimal cable line by repeating episodes of cable selection until target availability is satisfied. The result was compared with that of a general greedy algorithm to evaluate the reduction in construction costs.