Himawari-8 정지궤도 위성 영상을 활용한 딥러닝 기반 산불 탐지의 효율적 방안 제시

이시현,강유진,성태준,임정호,Sihyun Lee,Yoojin Kang,Taejun Sung,Jungho Im 대한원격탐사학회 2023 大韓遠隔探査學會誌 Vol.39 No.5

As wildfires are difficult to predict, real-time monitoring is crucial for a timely response. Geostationary satellite images are very useful for active fire detection because they can monitor a vast area with high temporal resolution (e.g., 2 min). Existing satellite-based active fire detection algorithms detect thermal outliers using threshold values based on the statistical analysis of brightness temperature. However, the difficulty in establishing suitable thresholds for such threshold-based methods hinders their ability to detect fires with low intensity and achieve generalized performance. In light of these challenges, machine learning has emerged as a potential-solution. Until now, relatively simple techniques such as random forest, Vanilla convolutional neural network (CNN), and U-net have been applied for active fire detection. Therefore, this study proposed an active fire detection algorithm using state-of-the-art (SOTA) deep learning techniques using data from the Advanced Himawari Imager and evaluated it over East Asia and Australia. The SOTA model was developed by applying EfficientNet and lion optimizer, and the results were compared with the model using the Vanilla CNN structure. EfficientNet outperformed CNN with F1-scores of 0.88 and 0.83 in East Asia and Australia, respectively. The performance was better after using weighted loss, equal sampling, and image augmentation techniques to fix data imbalance issues compared to before the techniques were used, resulting in F1-scores of 0.92 in East Asia and 0.84 in Australia. It is anticipated that timely responses facilitated by the SOTA deep learning-based approach for active fire detection will effectively mitigate the damage caused by wildfires.

광디스크 드라이브에서 ref_T. E신호 와 샘플펄스 신호를 이용한 평균 탐색시간 개선에 관한 연구

이시현,김계국,김형래,Lee, Si-Hyun,Kim, Kye-Kook,Kim, Hyung-Lea 한국음향학회 1995 韓國音響學會誌 Vol.14 No.4

본 논문에서는 광디스크 드라이브가 디스크상의 데이터를 탐색하는데 소요되는 평균탐색 시간 (Average Seek Time)을 개선하기 위한 방법으로 트랙추적 기준신호 (ref_T. E)와 샘플펄스 신호를 사용하여 평균탐색시간을 줄일수 있는 새로운 알고리즘을 제안 하였다. ref_T. E신호와 샘플펄스 신호를 사용하여 트랙을 탐색할 경우 목적트랙으로 이동한 다음 다시 위치를 확인하고 보상할 필요가 없도록하여 평균탐색시간을 개선하였다. 실험결과 28sec의 평균탐색시간을 보였다. In this paper, we design the new high-speed seek algorithm which can access the data of disk (in 3.5-inch optical disk drive). When seek the target track on optical disk in high-speed using the ref-T. E(Reference Tracking Error) and sample pulse signal, it's always possible high-speed seek without re-check and compensation for error by the ref_T. E and sample pulse signal. The performance test result is represented as follow ; it is satify the average seek time of 28mses.

The Impedance Analysis of Multiple TSV-to-TSV

이시현,Lee, Sihyun The Institute of Electronics and Information Engin 2016 전자공학회논문지 Vol.53 No.7

In this paper, we analyze the impedance analysis of vertical interconnection through-silicon vias (TSV) that is being studied for the purpose of improving the degree of integration and an electric feature in 3D IC. Also, it is to improve the performance and the degree of integration of the three-dimensional integrated circuit system which can exceed the limits of conventional two-dimensional a IC. In the future, TSV technology in full-chip 3-dimensional integrated circuit system design is very important, and a study on the electrical characteristics of the TSV for high-density and high-bandwidth system design is very important. Therefore, we study analyze the impedance influence of the TSV in accordance with the distance and frequency in a multiple TSV-to-TSV for the purpose of designing a full-chip three-dimensional IC. The results of this study also are applicable to semiconductor process tools and designed for the manufacture of a full-chip 3D IC. 본 논문에서는 기존의 2D IC의 성능을 개선하고 3D IC의 집적도와 전기적인 특성을 개선하기 위한 목적으로 연구되고 있는 TSV (Through Silicon Via)의 임피던스를 해석하였다. 향후 Full-chip 3D IC 시스템 설계에서 TSV는 매우 중요한 기술이며, 높은 집적도와 광대역폭 시스템 설계를 위해서 TSV에 대한 전기적인 특성에 관한 연구가 매우 중요하다. 따라서 본 연구에서는 Full-chip 3D IC를 설계하기 위한 목적으로 다중 TSV-to-TSV에서 거리와 주파수에 따른 TSV의 임피던스 영향을 해석하였다. 또한 이 연구 결과는 Full-chip 3D IC를 제조하기 위한 반도체 공정과 설계 툴에 적용할 수 있다.

$Nios^{(R)}$ II 임베디드 프로세서를 사용한 병렬처리 시스템의 설계 및 구현

이시현,Lee, Si-Hyun 한국컴퓨터정보학회 2009 韓國컴퓨터情報學會論文誌 Vol.14 No.11

In this thesis, we discuss the implementation of parallel processing system which is able to get a high degree of efficiency(size, cost, performance and flexibility) by using $Nios^{(R)}$ II(32bit RISC(Reduced Instruction Set Computer) processor) embedded processor in DE2-$70^{(R)}$ reference board. The designed Parallel processing system is master-slave, shared memory and MIMD(Mu1tiple Instruction-Multiple Data stream) architecture with 4-processor. For performance test of system, N-point FFT is used. The result is represented speed-up as follow; in the case of using 2-processor(core), speed-up is shown as average 1.8 times as 1-processor's. When 4-processor, the speed-up is shown as average 2.4 times as it's.

돌관공사 시나리오 기반 공기-비용 최적화 모델 개발

이시현,이승현,손재호,Lee, Sihyun,Lee, Seounghyun,Son, Jaeho 한국건설관리학회 2016 한국건설관리학회 논문집 Vol.17 No.3

최근 건설공사의 규모와 복잡성이 현저하게 증가함에 따라 건설비용이 상승하게 되었다. 많은 건설공사가 날씨, 노동력 공급, 장비 구매, 사고 등과 같은 다양한 요소들로 인하여 당초 계획했던 공사기일 내에 완공되지 못하고 있다. 계획된 시간 내에 공사를 완공하기 위하여 돌관공사를 시행하여야 한다. 하지만 돌관공사를 위한 결정들이 현장 소장들의 경험에만 의지하고 있는 실정이다. 그러므로 이 논문은 작업조의 투입과 작업시간의 조합으로 생길 수 있는 다양한 돌관공사 시나리오 중 최적의 대안을 선정할 수 있는 TCTO 모델을 제안하고자 한다. 개발된 모델은 실무적인 제약조건을 만족시키는 최적의 공정계획을 제공할 수 있다. 더 나아가서 제안된 모델에 자원평준기능을 포함하게 되면 보다 실용적인 모델이 될 수 있을 것으로 예상된다. Recently, the cost of construction projects has escalated due to a significant increase in size and complexity. Many construction projects have failed to meet their originally intended project deadline due to various factors such as weather, labor supply, equipment, procurement, accidents, etc. Consequently, emergency construction work scenario has to be implemented in order to shorten the duration and satisfy the original estimated schedule. However, many critical decisions in emergency scenario rely solely on the experience of a construction manager. Thus, this paper proposes TCTO optimization model to decide the most effective alternative out of various working scenarios which are generated by the combination of work group and work time. The developed TCTO model provides the optimum schedule that satisfies the practical constraints. Future research could involve the integration of resource leveling with the proposed model. This would make the model more versatile.

유두종증을 동반하지 않은 융합성 망상 유두종증

이시현 ( See Hyun Lee ),안지영 ( Ji Young Ahn ),박미연 ( Mi Youn Park ) 대한피부과학회 2011 대한피부과학회지 Vol.49 No.11

Confluent and reticulated papillomatosis (CRP) was first described as a relatively rare dermatosis. CRP is characterized by slightly hyperkeratotic pigmented papules that are confluent in the center and reticulated at the periphery, located on the neck, abdomen, intermammary, and interscapular regions. Histopathologically, lesions typically reveal orthohyperkeratosis, papillomatosis, and focal acanthosis. A 20-year-old man presented with a 2-year history of slightly pruritic lesions on the chest, abdomen, back, and upper extremities. The lesions were brownish papules and plaques in a reticulated and coalescing pattern. Histologically, a basket-weave pattern of orthohyperkeratosis and mild acanthosis were seen. However, there was no significant papillomatosis, even in multiple sections. Periodic acid Schiff stain was negative for fungi. The patient was treated with doxycycline, 200 mg daily, for 4 weeks. The lesions completely resolved and did not recur during 12 months of follow-up. We report a rare case of CRP without papillomatosis. (Korean J Dermatol 2011;49(11):1010∼1013)

건강한 환자에서 발생한 대칭성 이중성 대상포진

이시현 ( See Hyun Lee ),정혜정 ( Hye Jung Jung ),박미연 ( Mi Youn Park ),안지영 ( Ji Young Ahn ) 대한피부과학회 2011 대한피부과학회지 Vol.49 No.12

Herpes zoster duplex, particularly herpes zoster duplex symmetricus, is a very rare manifestation of herpes zoster that occurs in immunocompetent patients. A 23-year-old Korean man presented with grouped erythematous, ruptured, crusted vesicles on plaques and papules on his forehead and both temporal areas. He had unexplained pain around the cutaneous lesions for the past 2 weeks, and the vesicles developed 1 week ago. A Tzanck smear test of the skin lesion showed multinucleated giant cells. A punch biopsy taken from the vesicle on the forehead revealed an intraepidermal vesicle with acantholysis and balloon cells at the floor of the vesicle. He was diagnosed with herpes zoster involving bilateral dermatomes. (Korean J Dermatol 2011;49(12):1098~1101)

색소성 섬유상피종 와 문헌 고찰

이시현 ( See Hyun Lee ),안지영 ( Ji Young Ahn ),박미연 ( Mi Youn Park ) 대한피부과학회 2012 대한피부과학회지 Vol.50 No.5

Fibroepithelioma of Pinkus is generally accepted as a low-risk variant of basal cell carcinoma. A 66-year-old man was presented with a solitary dark red nodule with superficial erosion on his right groin. It tended to bleed, but was otherwise asymptomatic. Histopathologically, the tumor was composed of long, thin, branching and anastomosing strands of basaloid cells, which extends from the epidermis into the fibromucinous stroma. Basaloid tumor cells were palisaded at the periphery of the strands, and small buds were seen projecting from the epithelial strands. Significant amounts of melanin pigment were deposited in the papillary and reticular dermis, and the stroma between the tumor cords and also inside the tumor cells. The lesion was completely excised with clear margin. We report a case of pigmented fibroepithelioma of Pinkus with review of the literature in this communication. (Korean J Dermatol 2012;50(5):460∼463)

자율주행 드론 충돌회피 알고리즘에 관한 연구

이시현(Si-Hyun Lee),문소희(So-Hee Moon),오영휴(Young-Hyu Oh),김경식(Kyung-Sik Kim),신요안(Yoan Sin) 한국통신학회 2016 한국통신학회 학술대회논문집 Vol.2016 No.11

강화학습을 적용한 모바일로봇의 협업운송 제어

이시현(S. H. Lee),이귀형(G. H. Lee) 한국생산제조학회 2021 한국생산제조시스템학회 학술발표대회 논문집 Vol.2021 No.12