스마트그리드 AMI 환경을 위한 전방 보안성이 강화된 ID기반 인증 기법

박대일 ( Dae Il Park ),여상수 ( Sang Soo Yeo ) 한국항행학회 2013 韓國航行學會論文誌 Vol.17 No.6

본 논문에서는 기존에 연구된 AMI망 환경에서 동적 ID기반 인증 프로토콜 KL기법의 취약점을 분석하였고, 기존 연구의 보안요구사항을 만족하면서도 추가적으로 전방 보안성을 가지도록 하는 기법 두 가지를 제안한다. 첫번째 기법에서는 전력사 내의 상위 시스템인 MDMS를 시간동기화 서버로 사용하여 댁내의 스마트그리드 기기와 시간동기화 하여, 매 세션마다 OTP함수로 만들어지는 새로운 비밀값으로 인증을 진행한다. 두 번째 기법에서는 비공개 값의 해시체인을 사용하여 인증을 진행함으로써, 매 세션마다 새로운 비밀값을 사용한다. 제안하는 두 가지 기법은 지역 및 통신 환경에 따른 장·단점이 있을 것으로 보이며 이를 통해 AMI망 환경에 따라 제안기법을 효율적으로 선택하여 적용할 수 있을 것으로 예상한다. In this paper, we analyse the vulnerabilities of KL scheme which is an ID-based authentication scheme for AMI network, and propose two kinds of authentication schemes which satisfy forward secrecy as well as security requirements introduced in the previous works. In the first scheme, we use MDMS which is the supervising system located in an electrical company for a time-synchronizing server, in order to synchronize smart grid devices in home, and we process device authentication with a new secret value generated by OTP function every session. In the second scheme, we use a secret hash-chain mechanism for authentication process, so we can use a new secret value every session. The proposed two schemes have strong points and weak points respectively and those depend on the services area and its environment, so we can select one of them efficiently considering real aspects of AMI environment.

호칭어를 이용한 스마트폰 주소록 기능 개선

박대일 ( Dae-il Park ),여상수 ( Sang-soo Yeo ) 한국정보처리학회 2013 한국정보처리학회 학술대회논문집 Vol.20 No.2

기존의 휴대용 기기에서 내장되어 사용되는 주소록에 대하여 알아보고, 이를 바탕으로 생활에서 관용적으로 사용되는 호칭어를 통한 주소록 기능 개선에 대해 제안한다.

사료를 통한 Benzo(a)pyrene 노출에 따른 조피볼락, Sebastes schlegeli의 생화학 및 조직병리학적 변화

박대국 ( Dae Kuk Park ),김재원 ( Jae Won Kim ),지정훈 ( Jung Hoon Jee ),박수일 ( Soo Il Park ),강주찬 ( Ju Chan Kang ) 한국환경생물학회 2004 환경생물 : 환경생물학회지 Vol.22 No.3

사료를 통한 benzo(a)pyrene이 조피볼락, Sebastes schlegeli의 lipid peroxidation (LPO), superoxide dismutase (SOD) 활성과 간 조직의 병변 현상에 미치는 영향을 연구하기위해 0 (대조구), 0.5, 1.0, 1.5, 2.0 mg kg^(-1) 농도의 사료를 조제하여 30일간 급이하였다. LPO는 2.0 mg kg^(-1) 농도구에서 전 실험기간 동안 유의적으로 증가하였고, SOD 활성도 2.0 mg kg^(-1) 농도구에서 30일째에 유의적으로 증가하였다. 간 조직 검경시 10일째에 1.0 mg kg^(-1) 이상의 농도구에서 세포비대가 나타났고, 같은 농도에서 periodic acid-Schiff (PAS) 염색시 양성으로 나타나는 granule이 30일째에 나타났고, 2.0 mg kg^(-1) 농도구에서는 20일째부터 관찰되었다. 그리고, 30일째 2.0 mg kg^(-1) 농도구의 일부 어체에서는 간 세포의 괴사가 관찰되었다. Experiments were carried out to investigate the lipid peroxidation (LPO), superoxide dismutase (SOD) activity and histopathological change of hepatic tissue for rockfish, Sebastes schlegeli after feeding sub-chronic dietary Benzo(a)pyrene (BaP) in the concentration of 0 (control), 0.5, 1.0, 1.5, 2.0 mg kg^(-1) dry food of diet for 30 days. In 2.0 mg kg^(-1) dry food group, the significant increase of LPO was observed in all period, and SOD activity was incresed at 30 days significantly in the same concentration. In the histological investigation of liver, there was the swelling of hepatic cells at 10 days over the 1.0 mg kg^(-1) dry food concentration. At 30 days Periodic acid- Schiff (PAS) positive granule was observed in the same group and at 20 days was observed in 2.0 mg kg^(-1) dry food group. And there was necrosis of hepatic cell in some fish of 2.0 mg kg^(-1) dry food group at 30 days.

인버터 구동 유도전동기에서 과도전압의 측정과 분석

박대원(Dae-Won Park),김일권(Il-Kwon Kim),최수연(Su-Yeon Choi),박찬용(Chan-Yong Park),길경석(Gyung-Suk Kil) 한국철도학회 2007 한국철도학회 학술발표대회논문집 Vol.- No.-

Induction motors are the main driving force of electric vehicles and operated by pulse width modulation (PWM) inverters in speed control. Contrary to full-voltage operation of induction motors, inverter-fed induction motors (IFM) generates transient overvoltages up to 10 ㎸/us and transient overvoltages accelerate the deterioration of winding insulation. We investigated transient overvoltages produced by the operation of IFM and analyzed its peak value and dv/dt depending on power cable length and operation frequency. The experimental results showed that transient overvoltages measured at the motor terminal increased with the cable length between inverter and motor.

연료전지 무인기 탑재용 수소발생기의 성능평가

박대일(Dae Il Park),김성욱(Sung Uk Kim),김동민(Dong Min Kim),김태규(Taegyu Kim) 한국항공우주학회 2011 韓國航空宇宙學會誌 Vol.39 No.7

연료전지 무인기 탑재용 수소발생기의 온도환경변화에 따른 성능평가를 수행하였다. 수소 저장 및 발생을 위해 화학수소화물 중 수소함량이 높고 저장성이 우수한 수소화붕소 나트륨(NaBH₄)을 연료로 사용하였으며, 촉매를 이용한 가수분해반응을 통해 수소를 발생 하였다. 수소발생기의 온도환경변화를 위한 저온 및 고온 챔버를 각각 준비하였으며, 온도범위는 -20℃ 에서 60℃ 까지 20℃의 간격으로 설정하였다. 20과 25wt.%의 NaBH₄ 용액 농도에서 수소발생기의 수소발생률과 반응기와 분리기의 온도변화를 측정하였다. 수소 발생률은 반응주기가 반복될수록 감소하였으며, 저온 환경에서는 높은 수소발생률을 보였지만, 고온 환경에서는 수소발생률이 급격히 감소하였다. 수소발생률의 감소는 촉매유실과 촉매표면의 NaB0₂ 도포가 원인으로 확인되었다. Performance of a hydrogen generator for a fuel cell unmanned aircraft was evaluated as the change of temperature environment. Sodium borohydride (NaBH₄) was used as a hydrogen source due to its high hydrogen content and good storability. The hydrogen gas was generated by the hydrolysis reaction using a catalytic reactor. Reaction chambers were set up with the range of temperatures from -20 to 60 ℃. The hydrogen generation rate and temperatures changes of reactor and separator were measured at the NaBH₄ concentrations of 20 and 25wt. %. As a result, the hydrogen generation rate was decreased as the repeated reaction cycles. It showed that the hydrogen generation rate was stable at low temperature, while at high temperature the hydrogen generation rate was rapidly decreased. The performance degradation was mainly caused by the catalyst loss and NaBO₂ deposition on the catalyst surface.

비매개변수적 빈도해석 방법을 이용한 서울 지점 IDF 곡선의 유도

박대형(Park Dae-Hyeong),문영일(Moon Young-Il),차영일(Cha Young-Il),정민수(Jung Min-Su) 대한토목학회 2003 대한토목학회 학술대회 Vol.2003 No.10

센서 네트워크 환경에서의 데이터 처리 메커니즘

박대현(Dae-Ryun Park),김영준(Young-Jun Kim),이정훈(Jeong-Hoom Lee),정일영(Il-Young Chong) 대한전자공학회 2007 대한전자공학회 학술대회 Vol.2007 No.7

The effective data processing mechanism in the sensor network means data stream model and real-time query processing model for real-time processing of stream data. This mechanism can improve satisfaction of users and reduce delay rate of data processing. In this paper, we explain the problem which is occurred when users need to search certain information among information of stream data and describe reduction model of delay rate according to data transmission.

결막 뮬러근 절제술의 임상 결과와 수술 성공에 미치는 요인

박대일,하성우,유혜린,Dae Il Park,Sung Woo Ha,Helen Lew 대한안과학회 2011 대한안과학회지 Vol.52 No.11

Purpose: To investigate clinical outcomes and to analyze the factors of successful treatment of conjunctiva-Müller muscle resection (CMMR) in patients with mild to moderate ptosis. Methods: The medical records of 22 patients (30 eyes) with upper lid ptosis were retrospectively reviewed. All patients underwent conjunctiva-Müller muscle resections, and four patients (seven eyes) underwent concurrent upper lid blepharoplasty. The mean follow-up period was 81.62 ± 21 days. Pre- and post-operative MRD1, IPF and pupil to brow distance were measured using the Image J program. A preoperative phenylephrine test and a pathologic examination were performed to analyze the presence of Müller’s muscle and the tear secreting glands from the CMMR specimens. Results: The overall success rate of the procedure was 93%. Postoperatively, the MRD1 increased on average by 1.47 mm (p = 0.00) and increased by an average of 1.72 mm when the phenylephrine test response was greater than 2 mm and by 0.99 mm when the response less than 2 mm. The Müller muscle was observed in every specimen. Conclusions: Conjunctiva-Müller muscle resection is an effective and safe method for treating mild to moderate ptosis, for which the preoperative phenylephrine test result is the most important factor for surgical success. J Korean Ophthalmol Soc 2011;52(11):1263-1268

미숙아의 안축장에 영향을 미치는 요인에 대한 분석

박대일,하성우,박성배,윤영수,Dae Il Park,MD,Sung Woo Ha,MD,Seong Bae Park,MD,Young Soo Yun,MD 대한안과학회 2010 대한안과학회지 Vol.51 No.1

Purpose: To analyze the effect of presence with or absent of retinopathy of prematurity (ROP) and its stage, birth weight, conceptual age and associated diseases on the axial length of premature infants’ eye. Methods: A total of 102 eyes of 51 premature infants less than 36 weeks of conceptual age were evaluated in this study. Fundus examination for ROP and axial length measurement were conducted at 40, 52 and 64 weeks of postconceptual age. The medical records were reviewed retrospectively. Independent t-test analysis, simple regression analysis, and one-way ANOVA were performed to assess the influence of each factor on axial length. Results: The mean axial length at 40, 52 and 64 weeks were 17.35, 18.80 and 19.78 mm, respectively. The mean axial length with and without ROP at 40 weeks were 17.10 mm and 17.54 mm, respectively, which were statistically significant (p=0.000). There was a significant decrease in axial length at 40 weeks in the higher ROP stage (p<0.05). Axial length and birth weight showed positive correlation with statistical significance at 40 weeks, while these parameters showed no significant correlation at 64 weeks. Axial length and conceptual age showed a positive correlation with statistical significance at 40 weeks (p=0.000), yet a negative correlation at 64 weeks with no statistical significance (p=0.306). A significant difference was not observed between sex and the associated diseases. Conclusions: The factors that affect the axial length of an infants’eye at 40 weeks were ROP and its stage, birth weight, and conceptual age. Additionally, there was no significant relationship between sex and the associated diseases. J Korean Ophthalmol Soc 2010;51(1):81-87

서울 강우량과 남방진동지수간의 저빈도 관계 분석

박대형,황성환,문영일,Park, Dae-Hyeong,Hwang, Seong-Hwan,Mun, Yeong-Il 한국수자원학회 2000 한국수자원학회논문집 Vol.33 No.1