평판 사이 정방형실린더 주위의 난류 유동에 대한 LES

김도형,양경수,Kim, Do-Hyeong,Yang, Gyeong-Su 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.2

Turbulent flow past a square cylinder confined in a channel is numerically investigated by Large Eddy Simulation(LES). The main objectives of this study are to verify the experimental results of Nakagawa et al.[Exp. in Fluids, Vol. 27, 3, pp. 284∼294, 1999] by LES and to obtain related flow information in detail. The LES results obtained are in excellent agreement with the experiment both qualitatively and quantitatively. The passive paticles numerically released into the flow field clearly show the barman vortex street. However, the vortices shed from the cylinder are significantly affected by the presence of the plates. Futhermore, periodic and alternating vortex-rollups are observed in the vicinity of the plates. The rolled-up vortex is convected downstream together with the corresponding Karman vortex forming a counter-rotating vortex pair. It is also revealed that the cylinder greatly enhances mixing process of the flow.

INRA를 통해서 본 국제 원자력 안전 규제 동향

김도형,Kim, Do-Hyeong 한국원자력산업회의 2008 원자력산업 Vol.28 No.4

SOFC 분리판용 Fe-Cr 합금의 특성에 미치는 합금성분의 영향

김도형,전재호,김승구,전중환,Kim, Do-Hyeong,Jun, Jae-Ho,Kim, Seung-Goo,Jun, Joong-Hwan 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.12

The oxidation resistance and electrical conductivity of various commercial ferritic stainless steels including STS444 were tested in an air atmosphere at $700^{\circ}C$. Crofer22 developed specially for SOFC interconnect was also examined for the aim of comparing with the test results of STS444. Although STS444 exhibited higher oxidation resistance than Corfer22, the electrical conductivity of the scale formed on Crofer22 was higher, indicating that the resistivity of scale formed on Crofer22 is much lower than that of STS444. To gain a better understanding of the relation between oxidation behavior and electrical conductivity, the oxide scales formed on STS444 and Crofer22 were analyzed in terms of the structure, composition, and phase. Consequently, the influence of alloying elements on electrical conductivity of Fe-Cr alloys was discussed.

MDAP와 우리의 대응

김도형,Kim, Do-Hyeong 한국원자력산업회의 2006 원자력산업 Vol.26 No.6

이미다졸륨 고분자 코팅을 통한 음이온교환막의 물분해 특성 제어

김도형,박진수,강문성,Kim, Do-Hyeong,Park, Jin-Soo,Kang, Moon-Sung 한국막학회 2015 멤브레인 Vol.25 No.2

In this study, novel pore-filled anion-exchange membranes (PFAEMs) with low electrical resistance, high permselectivity, and low water-splitting flux property under a concentration polarization condition have been developed for the enhancement in the efficiency of electrochemical water treatment processes. The base membranes have been prepared by filling a copolymer containing quaternary ammonium groups with an excellent ion-exchange capability into a porous polyolefin substrate, showing a high performance superior to that of a commercial membrane. In addition, it was confirmed that the electrochemical membrane performances are preserved while the water-splitting flux is effectively controlled by coating an imidazolium polymer onto the surface of the base membrane. The prepared PFAEMs revealed remarkably low electrical resistances of about 1/6~1/8 compared to those of a commercial membrane, and simultaneously low water-splitting flux comparable with that of cation-exchange membranes under a concentration polarization condition. 본 연구에서는 이온교환막을 이용한 전기화학적 수처리 공정의 효율을 향상시키기 위해 낮은 전기적 저항, 높은 이온선택 투과성, 및 농도분극 조건에서 낮은 물분해 플럭스 특성을 갖는 새로운 세공충진 음이온 교환막을 개발하였다. 다공성 폴리올레핀 기재에 이온교환능이 우수한 4급 암모늄기를 포함한 공중합 고분자를 충진하여 상용막 이상의 성능을 갖는 기저 멤브레인을 제조하였다. 또한 기저 막 표면에 이미다졸륨 고분자를 코팅하여 전기화학적 성능을 유지하며 동시에 물분해 플럭스를 효과적으로 제어할 수 있음을 확인하였다. 제조된 세공충진 음이온 교환막은 상용막 대비 약 1/6~1/8 수준의 매우 낮은 전기적 저항을 나타내었으며 동시에 농도분극 조건에서 양이온 교환막 수준의 낮은 물분해 플럭스를 나타내었다.

금융회사를 위한 기업 정보보호 포털(EISP) 시스템의 설계 및 구현

김도형,Kim, Do-Hyeong 한국융합보안학회 2021 융합보안 논문지 Vol.21 No.1

금융회사는 금융정보를 보호하기 위해 정보보호 전략 및 계획을 수립하고 정보보호 관리체계 운영, 정보보호 시스템 구축 및 운영, 취약점 점검, 보안관제 등 다양한 정보보호 활동을 하고 있다. 본 논문에서는 금융회사에서 수행 중인 각종 정보보호 활동에 대한 가시성을 확보하고 통합 관리할 수 있는 금융회사를 위한 기업 정보보호 포털 시스템을 제시하고자 한다. 기업 정보보호 포털 시스템은 정보보호 부서의 활동을 시스템화하여 정보보호 활동이 정보보호 부서만의 활동이 아닌 최고경영자부터 임직원까지 참여할 수 있도록 통합된 환경을 제공한다. 이를 통해 최고경영진이 기업경영에 정보보호를 반영할 수 있는 정보보호 거버넌스로도 활용할 수 있다. To protect financial information, financial companies establish strategies and plans for information security, operate information security management systems, establish and operate information security systems, check vulnerabilities, and secure information. This paper aims to present an information security portal system for financial companies that can gain visibility into various information security activities being undertaken by financial companies and can be integrated and managed. The information security portal system systemizes the activities of the information security department, providing an integrated environment for information security activities to participate from CEOs to executives and employees, not just from the information security department. Through this, it can also be used as information security governance that can be used by top executives to reflect information security in corporate management.

국내 해상풍력 타당성 검토 및 추진전략

김도형,Kim, Do-Hyeong 한국전기전자재료학회 2011 전기전자재료 Vol.24 No.3

고성능 역전기투석을 위한 세공충진 음이온교환막의 개발

김도형,송현비,윤경석,강문성,Kim, Do-Hyeong,Song, Hyeon-Bee,Yoon, Kyungseok,Kang, Moon-Sung 한국막학회 2022 멤브레인 Vol.32 No.5

Reverse electrodialysis (RED) is one of the promising eco-friendly renewable energy technologies which can generate electricity from the concentration difference between seawater and freshwater by using ion-exchange membranes as a diaphragm. The ion-exchange membrane is a key component that determines the performance of RED, and must satisfy requirements such as low electrical resistance, high permselectivity, excellent durability, and low manufacturing cost. In this study, pore-filled anion-exchange membranes were fabricated using porous polymer substrates having various thicknesses and porosity, and the effects of ion-exchange polymer composition and membrane thickness on the power generation performance of RED were investigated. When the electrical resistance of the ion-exchange membrane is sufficiently low, it can be confirmed that the RED power generation performance is mainly influenced by the apparent permselectivity of the membrane. In addition, it was confirmed that the apparent permselectivity of the membranes can be improved through IEC, crosslinking degree, membrane thickness, surface modification, etc., and the optimum condition must be found in consideration of the trade-off relationship with electrical resistance.

윷놀이에서 말이 가는 거리의 분포

김도형,오창혁,Kim, Do-Hyeong,Oh, Chang-Hyuck 한국데이터정보과학회 2010 한국데이터정보과학회지 Vol.21 No.6

한 조로 사용 되는 네 개의 윷가지의 크기와 모양이 같아서 각 윷가지의 등이 나올 확률이 같은 윷놀이를 생각한다. 윷놀이에서는 모나 윷이 나오면 한 번 더 던지는 규칙이 있으므로, 한 사람의 차례에서 윷을 던져 말이 가는 거리 X에 관심이 있게 된다. 따라서, 거리 X에 대한 확률질량함수를 구하고, 각 윷가락의 등이 나올 확률의 몇 개의 값에 대하여 확률을 표로 나타낸다. 또한, 거리 X의 기댓값, 분산, 왜도, 첨도를 구하며, 주어진 윷의 등의 확률의 몇 개 값에 대하여 값을 구하여 표로 나타낸다. We consider Yut board game with four Yut sticks which are of the same shape and the same size so that they have the same probability of showing back when they are tossed. Since, in Yut board game, a player have to toss four sticks one more when sawi Mo or sawi Yut appears, the player may be interested in the distance which Mal can move in one's turn. Therefore, the probability mass function of the distance is obtained and probabilities with several values of back probability are summarized in a table. Also, the expectation, the variance, the skewness, and the kurtosis of the distribution are calculated and their values are also tablized for some values of back probability.

원자력 안전

김도형,Kim, Do-Hyeong 한국원자력산업회의 2006 원자력산업 Vol.26 No.10