풍화대 지반에서의 쉴드 TBM 커터도구 선정 및 마모량 평가 (서울지하철 7호선연장 703공구 건설공사를 중심으로)

박준수,도덕수,김용일,정두석,Park, Jun-Su,Do, Deok-Su,Kim, Yong-Il,Jeong, Du-Seok 한국터널지하공간학회 2006 터널기술 Vol.8 No.3

다중모드 Cognitive Radio 통신 시스템을 위한 GBNSGA 최적화 알고리즘

박준수,박순규,김진업,김형중,이원철,Park, Jun-Su,Park, Soon-Kyu,Kim, Jin-Up,Kim, Hyung-Jung,Lee, Won-Cheol 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.3C

본 논문에서는 CR(Cognitive Radio)을 위해 사용자에게 최적의 통신 시스템 구성 변수들을 할당하기 위한 새로운 최적화 알고리즘인 GBNSGA(Goal-Pareto Based Non-dominated Sorting Genetic Algorithm)를 제안한다. 다중모드 선택적 CR 통신을 위해 사용되는 cognitive 엔진은 Mitola가 제안한 cognition 싸이클의 많은 논리 연산과정이 필요하다는 단점을 보완하기 위하여 일반적으로 유전자 알고리즘 기반의 접근 방식이 사용되고 있다. 본 논문에서는 cognitive 엔진의 효율적인 구동을 위하여 파레토(Pareto) 기반의 최적화 알고리즘인 NSGA(Non-dominated Sorting Genetic Algorithm)와 사용자 서비스의 요구사항을 goal로 설정하는 GP(Goal Programming)을 결합한 새로운 최적화 방법으로 GBNSGA를 제안하였으며, 시뮬레이션 수행을 통해 제안된 알고리즘이 요구사항에 적합한 다양한 해를 제공하고 최적화 수렴속도가 빠르다는 것을 확인하였다. This paper proposes a new optimization algorithm named by GBNSGA(Goal-Pareto Based Non-dominated Sorting Genetic Algorithm) which determines the best configuration for CR(Cognitive Radio) communication systems. Conventionally, in order to select the proper radio configuration, genetic algorithm has been introduced so as to alleviate computational burden along the execution of the cognition cycle proposed by Mitola. This paper proposes a novel optimization algorithm designated as GBNSGA for cognitive engine which can be described as a hybrid algorithm combining well-known Pareto-based NSGA(Non-dominated Sorting Genetic Algorithm) as well as GP(Goal Programming). By conducting computer simulations, it will be verified that the proposed method not only satisfies the user's service requirements in the form of goals. It reveals the fast optimization capability and more various solutions rather than conventional NSGA or weighted-sum approach.

충북 및 충주 지역의 수소산업 생태계와 가능성

박준수,Park, Jun Su 한국교통대학교 융복합기술연구소 2019 융ㆍ복합기술연구소 논문집 Vol.9 No.1

The government has designated the hydrogen industry as one of the three most innovative industries and is making a lot of investment and support. Chungcheongbuk-do and Chungju are developing strategies to foster local industries in line with these government policies. Hyundai Mobis's Chungju plant, located in Chungju, is the only fuel cell plant in Korea and is emerging as the center of hydrogen cars as the government's hydrogen mobility industry expands. Chungcheongbuk-do and Chungju City seek to attract relevant institutions and companies based on their regional strengths. In this paper, the current status of hydrogen industry in Chungcheongbuk-do and Chungju-si is discussed and future plans are discussed.

전항력을 이용한 회전 블레이드 냉각성능 향상 방안 연구

박준수,Park, Jun Su 한국교통대학교 융복합기술연구소 2016 융ㆍ복합기술연구소 논문집 Vol.6 No.1

The serpentine internal passage is located in turbine blade and it shows the variety heat transfer distribution. Especially, the Coriolis force, which is induced by blade rotation, makes different heat transfer distribution of the leading and trailing surfaces of serpentine internal passage. The different heat transfer is one of the reasons why the serpentine cooling passage shows low cooling performance in the rotating condition. So, this study tried to design the advanced the serpentine passage to consideration of the Coriolis force. The design concept of advanced serpentine cooling is maximizing cooling performance using the Coriolis force. So, the flow turns from leading surface to trailing surface in advanced serpentine passage to match the direction of Coriolis force and rotating force. We performed numerical analysis using CFX and compared the existing and advanced serpentine internal passage. This design change is induced the high heat transfer distribution of whole advanced serpentine internal passage surfaces.

사우디 라빅발전소 터빈 블레이드 파손 분석기술 현장 적용

박준수,Park, Jun Su 한국전력공사 2021 KEPCO Journal on electric power and energy Vol.7 No.1

한전에서 운영중인 사우디라빅발전소에서 저압터빈 블레이드가 파손되었다. 블레이드의 경우 터빈의 핵심부품으로서 증기를 활용하여 발전기를 회전시켜 전기를 생산하는데 필수 부품이다. 반복적인 사고발생을 예방하기 위해 조직분석, 운전신호 분석등을 활용하여 원인을 규명하였고, 대책을 제시하였다.

제트홀이 설치된 핀-휜 및 핀-휜/딤플 복합 배열을 사용한 내부유로에서의 열전달 향상

박준수,Park, Jun Su 한국교통대학교 융복합기술연구소 2015 융ㆍ복합기술연구소 논문집 Vol.5 No.1

A Pin-fin array is widely used to enhance the heat transfer in the internal cooling passage. The heat transfer distribution around the pin-fin is varied by the horseshoe vortex and flow separation. The difference of heat transfer coefficient induces the large thermal stress, which is one of the major reasons to break of hot components. So, it is required to enhance the heat transfer on the back side of pin-fin to solve the thermal stress problem. This study suggests the pin-fin with inclined jet hole and complex pin-fin/dimple array to enhance the heat transfer on the back side of pin-fin. The heat transfer coefficient is predicted by the numerical analysis, which is performed by CFX 14.0. The numerical results are obtained at Reynolds number, 10,000. The results show that the heat transfer on the back side of pin-fin is increased in both cases. Beside, the wake, which comes from dimple and jet, helps to develop the horseshoe vortex and increase the heat transfer on the next row pin-fin.

안면의 색소성 질환에서 Glycolic acid 박피술과 Tretinoin 박피술의치료 효과에 대한 비교연구

박준수 ( Jun Su Park ),김경호 ( Kyoung Ho Kim ),정기양 ( Kee Yang Chung ) 대한피부과학회 2003 대한피부과학회지 Vol.41 No.7

N/A Background : Chemical peels using glycolic acid and tretinoin are known to be safe and effective for treating facial pigmentary lesions. Objective : We evaluated and compared the efficacy of tretinoin and glycolic acid peeling for facial pigmentary lesions by using a digital camera and L^(*)a^(*)b^(*) color scale in Adobe Photoshop 5.5^(??). Methods : Thirty eight patients with facial pigmentary lesions were treated with 50% glycolic acid and 1% tretinoin peelings. The treatment was performed 2-3 times per week for a period of 2 weeks and a half. Exposure time was 2 minutes for the glycolic acid and 6 hours for the tretinoin. Before and after the treatment, pigmentary lesions were evaluated using self evaluation forms and the L^(*)a^(*)b^(*) color system (Commission International de I`Eclairage) in Adobe Photoshop 5.5^(??) (Adobe Systems Incorporated, USA). Corneometer (Corneometer^(??) CM820, Courage Khazaka Electronic GmbH, Germany) was used for the evaluation of skin hydration before and after the treatment. Results : Facial pigmentary lesions were significantly improved in 10 out of 38 patients after 50% glycolic acid peeling and in 12 out of 38 patients after 1% tretinoin peeling. The state of hydration of the treated skin improved significantly after the peeling using both 50% glycolic acid and 1% tretinoin. Conclusion : Topical 1% tretinoin peeling is as effective as 50% glycolic acid peeling in the treatment of facial pigmentary lesions and more frequent peeling results in quicker improvement than the previous studies without significant side effects. (Korean J Dermatol 2003;41(7) : 841~846)

도시재생을 위한 상업 거리 경관에 나타난 주시 특성

박준수(Park, Jun-Su),김주연(Kim, Ju-Yeon) 대한건축학회 2017 대한건축학회 학술발표대회 논문집 Vol.37 No.1

The aim of this study was to find out the priorities of environmental factors that should be improved for street landscape in urban regeneration projects through eye-tracking experiment. That is, this study attempted to examine what area their gaze usually stays on street landscape. The experiment was conducted in a place that was previously used as a darkroom, where the environment was improved so as not to disturb the subject`s gaze. All of the participants were male, and they were shown street landscape image for 65 seconds on the monitor. The distance between the subject`s eyes and the monitor was kept at 650mm. and the monitor size was 510x287mm. To analyze data, this study divided the experimental image into eight AOIs like banner, light, air sign, chair, pot, pavements, tree, and sign. The fixation time and count for AOIs were analyze. AISo, we evaluated the fixation time and count after reflection area of AOIs ratio. The results of this study were as follows; First, it was found out that people`s gaze are attracted to banners and air sign in commercial street. Second, this study found out that a person gazes on the roadside tree, but it is not seen as part of rejecting factor but as a part of nature, Third, pavements has very little effect on human gaze In conclusion, our findings provide basic data that help to plan street landscape for urban regeneration reasonably.

위치정보제공자와 연계한 인터넷전화 긴급전화 시스템

박준수(Jun-Su Park),김희동(Hee-Dong Kim) 한국정보과학회 2010 한국정보과학회 학술발표논문집 Vol.37 No.1D

WLAN 기술의 발전과 AP의 증가로 WLAN 기반 인터넷전화의 보급이 증가함에 따라 인터넷전화의 긴급 통화 서비스 제공이 중요한 문제가 되었다. 국내외에서는 긴급통화 서비스를 인터넷전화의 필수요건으로 규정하고, 기술표준을 제정하여 인터넷전화 사업자들에게 이를 적용하고 있다. WLAN 인터넷전화는 이동성이 보장되기 때문에 긴급통화 서비스 제공 시 사용자의 정확한 위치정보 전달이 중요하다. 본 논문에서는 위치정보 획득 방법을 기반으로 위치정보제공자와 연계를 통한 인터넷전화 긴급전화 서비스 제공 구조를 제안한다.

SSD 스토리지 시스템을 위한 효율적인 DRAM 버퍼 액세스 스케줄링 기법

박준수(Jun Su Park),황용중(Yong Joong Hwang),한태희(Tae Hee Han) 大韓電子工學會 2011 電子工學會論文誌-SD (Semiconductor and devices) Vol.48 No.7

최근 NAND 플래시 메모리를 이용한 새로운 저장매체인 SSD(Solid State Disk)가 모바일 기기를 중심으로 HDD(Hard Disk Drive)를 대체하면서 가격대비 성능을 향상시키려는 연구가 다양한 접근 방식을 통해 진행 중이다. 병렬처리를 통한 NAND 플래시 대역폭 향상을 위해 채널수를 확장하면서 호스트(PC)와 NAND 플래시 간의 버퍼 캐시의 역할을 하는 DRAM 버퍼가 SSD 성능 개선의 bottleneck으로 작용하게 되었다. 이 문제를 해소하기 위해 본 논문에서는 DRAM Multi-bank를 활용한 스케줄링 기법을 통해 DRAM 버퍼 대역폭을 개선함으로써 저비용으로 SSD의 성능을 향상시키는 효과적인 방안을 제안한다. 호스트와 NAND 플래시 다중 채널이 동시에 DRAM 버퍼의 접근을 요청하는 경우, 이들의 목적지를 확인하여 DRAM 특성을 고려한 스케줄링 기법을 적용함으로써 bank 활성화 시간과 row latency에 대한 overhead를 감소시키고 결과적으로 DRAM 버퍼 대역폭 활용을 최적화할 수 있다. 제안한 기법을 적용하여 실험한 결과, 무시할만한 수준의 하드웨어 변경 및 증가만으로 기존의 SSD 시스템과 비교하여 SSD의 읽기 성능은 최대 47.4%, 쓰기 성능은 최대 47.7% 향상됨을 확인하였다. Recently, new storage device SSD(Solid State Disk) based on NAND flash memory is gradually replacing HDD(Hard Disk Drive) in mobile device and thus a variety of research efforts are going on to find the cost-effective ways of performance improvement. By increasing the NAND flash channels in order to enhance the bandwidth through parallel processing, DRAM buffer which acts as a buffer cache between host(PC) and NAND flash has become the bottleneck point. To resolve this problem, this paper proposes an efficient low-cost scheme to increase SSD performance by improving DRAM buffer bandwidth through scheduling techniques which utilize DRAM multi-banks. When both host and NAND flash multi-channels request access to DRAM buffer concurrently, the proposed technique checks their destination and then schedules appropriately considering properties of DRAMs. It can reduce overheads of bank active time and row latency significantly and thus optimizes DRAM buffer bandwidth utilization. The result reveals that the proposed technique improves the SSD performance by 47.4% in read and 47.7% in write operation respectively compared to conventional methods with negligible changes and increases in the hardware.