멀티 모달 지도 대조 학습을 이용한 농작물 병해 진단 예측 방법

이현석,여도엽,함규성,오강한,Hyunseok Lee,Doyeob Yeo,Gyu-Sung Ham,Kanghan Oh 대한임베디드공학회 2023 대한임베디드공학회논문지 Vol.18 No.6

With the wide spread of smart farms and the advancements in IoT technology, it is easy to obtain additional data in addition to crop images. Consequently, deep learning-based crop disease diagnosis research utilizing multimodal data has become important. This study proposes a crop disease diagnosis method using multimodal supervised contrastive learning by expanding upon the multimodal self-supervised learning. RandAugment method was used to augment crop image and time series of environment data. These augmented data passed through encoder and projection head for each modality, yielding low-dimensional features. Subsequently, the proposed multimodal supervised contrastive loss helped features from the same class get closer while pushing apart those from different classes. Following this, the pretrained model was fine-tuned for crop disease diagnosis. The visualization of t-SNE result and comparative assessments of crop disease diagnosis performance substantiate that the proposed method has superior performance than multimodal self-supervised learning.

총설 : 산림과학분야의 산림특용자원식물의 연구 -한국임학회지에 게재된 논문을 중심으로 -

이현석 ( Hyunseok Lee ),이재선 ( Jaeseon Yi ),안찬훈 ( Chanhoon An ),이정훈 ( Jeonghoon Lee ) 한국임학회 2015 한국산림과학회지 Vol.104 No.3

한국임학회지(1962년의 1권부터 2013년 102권 4호)에 게재된 산림특용자원식물 논문에서 대상식물을 식·음용식물, 약용식물, 사료식물, 조경식물, 섬유식물, 산업용 식물, 밀원식물, 바이오에너지/환경정화 식물, 염료/도료 및 희귀·멸종위기·특산식물로 분류하고, 그 연구내용에 따라 입지환경, 생태, 생리, 번식, 조림(무육과 재배 포함), 유전·육종, 분류(또는 식별), 병·충해와 방제, 동물피해와 방제, 성분분석과 추출물, 식생 또는 자생지 정보, 생물공학, 경영과 경제, 휴양 및 산림치유 및 총설로 구분하였다. 총 2,433편의 논문 중에서 특용자원식물 관련 논문은 611편으로 25.1%를 나타내었다. 연구내용에서 보면, 조림분야의 논문이 14.9%로 가장 높은 비율을 나타냈으며, 다음으로는 생리, 번식, 분류 및 유전·육종 등의 순으로 나타났다. 식물의 이용 목적에 따라서는 식·음용으로 이용된 식물이 26.5%로 가장 높게 나타났으며, 다음으로는 산업용, 바이오에너지/환경정화, 조경, 약용과 희귀·멸종위기·특산식물 등의 순으로 나타났다. 게재된 식물 중 연구빈도가 가장 높은 식물은 포플러류(62편)였으며, 밤나무, 잣나무, 아까시나무, 은행나무 등의 순으로 나타났다. 연구의 분야, 내용 및 대상식물 결과 등을 종합하여 보면, 1) 산림 내생물자원에 대한 자원적 가치 인식 제고, 2) 산림과학분야 다양한 영역에서의 생산, 경영 및 이용에 관한 연구, 3)식물정보의 데이터베이스 구축 및 타 과학 및 산업 분야의 흐름에 부응 및 4) 전통 식물 발굴 등이 산림특용자원식물 분야의 연구에서 깊이 고려되어야 할 것이다. The articles, published in the Journal of Korean Forest Society from Volume 1 (1962) to Volume 102 (2013), were investigated for the research trend analysis about forest plants for special purposes, i.e., edible plants, medicinal plants, feed resources, landscape plants, fiber plants, industrial usage, bee plants, bioenergy/ phytoremediation uses, dye materials, and rare/endangered/endemic plants. These research articles were classified again based on the contents of research into following categories - habitat environment, ecology, physiology, propagation, silviculture (including planting and tending), genetics and breeding, identification, pest and disease control, animal-related research, components analysis and extracts, vegetation survey, biotechnology, management, recreation and forest healing, and research review. Among the total 2,433 articles published, 611 (25.1%) were related to plants for special usage or purposes. The highest frequency (14.9%) in publications was found in the field of silviculture followed by physiology, propagation, identification, and genetics and breeding, respectively. On the bases of usage, edible plants showed higher frequency (26.5%) than others, followed by industrial purpose, bioenergy/phytoremediation usage, landscape plants, medicinal plants, and rare/endangered/endemic plants. Populus plant species was the most popular in research, showing 62 articles; and Castanea crenata 36; Pinus koraiensis 35; Robinia pseudoacacia 20; Ginko biloba 17, etc. Based on the survey and analysis, the following points are suggested: 1) improved evaluation of forest plants as non-wood resources, 2) expanding research topics on the basis of production, management, and utilization of non-wood forest resources, 3)management of database of forest plant information and encouragement needed to strengthen cooperative researches satisfying the needs of other industrial and scientific areas, and 4) encouraging to promote traditional knowledge based research on forest plants.

Enhancement of room temperature formability of strip cast AZ31 alloy sheet

Hyunseok Lee(이현석),W. Bang(방원규),Kiho Yun(윤기호),Dongkyun Choo(추동균),Ohduck Kwon(권오덕) 한국소성가공학회 2012 마그네슘 심포지엄 Vol.2012 No.11

투명 박막 리튬이차전지를 위한 LiNiPO₄ 박막의 광학 및 전기화학적 특성

이현석 ( Hyunseok Lee ),( Narendra S Parmar ),김광범 ( Kwang-bum Kim ),최지원 ( Ji-won Choi ) 한국센서학회 2018 센서학회지 Vol.27 No.1

Transparent olivine LiNiPO4 thin films on sapphire substrates were fabricated by radio frequency (RF) magnetron sputtering. The Xray diffraction patterns show these thin films have the phase of LiNiPO₄ with an ordered olivine structure indexed to the orthorhombic Pmna space group. LiNiPO₄ thin films deposited on sapphire substrates exhibit transmittance of about 83 %. It was confirmed that the LiNiPO₄ thin film exhibits a high potential of 5 V-class.

K9 자주포 동력장치용 연료냉각기 열유동 성능 해석 설계

이현석(Hyunseok Lee),배석정(Sukjung Bae),홍성목(Seongmok Hong),이호남(Honam Lee),박천명(Cheonmyung Park) 한국자동차공학회 2023 한국자동차공학회 부문종합 학술대회 Vol.2023 No.5

The K9 self-propelled artillery is developed with independent Korean technology, and has been exported to various countries in Europe and Asia due to its exceptional performance and practical experience. However, the coolers used in the K9 self-propelled artillery power unit are all imported, which limits the potential for exports. To address this issue, we aim to develop and localize components that can be applied to the K9 self-propelled artillery power units. In this study, we developed a 1D performance analysis program to facilitate the alternative development of fuel coolers. The program uses design variables of the fuel coolers shape and operating conditions to calculate analysis results. We conducted a parametric study of a fuel cooler using the program, varying the number of fuel tubes and offset fin pitch. Our analysis showed that as the number of fuel tubes increases, the amount of heat dissipation increases while the pressure drop of fuel and air decreases. Furthermore, as the offset fin pitch increases, the heat transfer area decreases, the flow path increases, and the heat dissipation and pressure drop on the fuel side decrease.

전기자동차용 CNT 히터의 난방 성능 평가

이현석(Hyunseok Lee),배석정(Sukjung Bae),허형석(Hyungseok Heo),이호성(Hoseong Lee),이병호(Byongho Lee) 한국자동차공학회 2020 한국자동차공학회 학술대회 및 전시회 Vol.2020 No.11

One of the most important factors in an electric vehicle is the mileage it can drive on a single charge. Many studies are being conducted on the effects on electric vehicle-mile. When the electric cabin heater is operated in the winter season, power consumption increases and vehicle-mile is significantly reduced. Development of heaters with low power consumption and high heating efficiency is needed. In this study, the performance of conventional positive temperature constant(PTC) heater was compared to a heater with carbon nanotube(CNT) material. Cabin heater was installed in the performance assessment equipment and the performance assessment was performed by simulating the winter season driving environment. Compared to conventional PTC heater, heat capacity of the CNT heater was greater. Pressure drop of CNT heater was high compared to the conventional PTC heater, but the difference was relatively small. CNT heater improved the heat-up rate by 34.2% over the conventional PTC heater.

집합동산담보의 활성화에 관한 입법론적 고찰

이현석(Lee, HyunSeok) 한양법학회 2011 漢陽法學 Vol.33 No.-

Many Countries including USA, Canada and Australia which undergoes the influence of British’s law system have been enforcing “The Floating Security System”. Otherwise “The Security of Inventory” has been recognized by theory or precedent in Germany and Japan. By the socio-economic needs in accordance with the development of capitalism in our country Korea recently, inventory is treated as one object in the law practice conventionally. Therefore, what is at issue in current civil law system is how to treat the security of inventory as a security object. The security of inventory is not used widely because the imperfection of public notification so-called the agreement on possession undermines the stability of security and occurs the risks of double transfer or bona fide acquisition. From these reasons, we suggest that the plan which gives strong legal effects in chattel security and activates the security of inventory is to introduce a new public notification. Otherwise many countries and the international organizations are making an effort to devise new means of security for increase and expansion of the security value by request of the national and international economic activity and of the mobility of financial capital. The movement to unify the chattel security system internationally or to make security by public notification is enhancing actively, and also the effect of that has resulted in significant achievements. The change of chattel security is appearing with different direction from the property law or the law principle for the real rights of security in continental law system because the chattel security system tends to be composed with the contents of common chattel law or common security law. The most characteristic changes of chattel security are that the numerus clausus principle is weakened and the freedom of contract is being recognized. In continental law system the parties can not create real rights of security or change its contents arbitrarily, since the numerus clausus principle that the types and contents of security are determined by law is applied as a dominant principle. But in new real rights law of security the chattel securities are integrated into one security right, and its contents can be decided by both parties’ agreements freely. This is the characteristic of common property law that does recognize not the numerus clausus principle but the freedom of contract. Also in new chattel security law the specific principle which is another dominant principle of property law is not recognized. The specific principle is that since the real right is the general right, the specification should be known to the third party. To be known to the third party the rights should be notified by registration of real property or by occupation of chattel, so the specific principle needs to be kept in order to implement the public notification method. But in new chattel security system, one security right is to be set without distinction whether the specific chattel or the inventory, the existing assets or the assets which will acquire in future, and the chattel or the bond. The only needs to contract is the agreement with the scope of chattel and bond between parties. And the mortgaged bond is not distinguished whether the specific bond or the multiple bond, the existing bond or the bond which will issue in future. It is enough that the details of the scopes for the mortgaged chattel and bond are clarified in the security contracts. This new chattel security system is more concerned with the practice than the theory, and is more pragmatic and reasonable. For these reasons, international transaction or international financial institutions are alleging to take advantage of this system. In order to increase and expand the security values, many countries and international organizations are doing every efforts to seek a new security means used throughout the world. Our country l

졸음운전 감소를 위한 첨단경고장치 도입방안

이현석(Lee,HyunSeok) 대한토목학회 2017 대한토목학회 학술대회 Vol.2017 No.10

APA 기반 온라인 파라미터 추정을 통한 IPMSM 센서리스 제어 특성 개선 연구

이현석(HyunSeok Lee),박제석(Jesuk Park),주상훈(SangHoon Ju),이근호(GeunHo Lee) 한국자동차공학회 2022 한국자동차공학회 학술대회 및 전시회 Vol.2022 No.11

수소전기상용차 냉각순환시스템용 고유량 제어 밸브 해석 설계

이현석(Hyunseok Lee),배석정(Sukjung Bae),허형석(Hyungseok Heo),박찬진(Chanjin Park) 한국자동차공학회 2023 한국자동차공학회 부문종합 학술대회 Vol.2023 No.5

As environmental and resource concerns escalate, eco-friendly vehicles have gained momentum in the global automobile market. Among them, fuel cell electric vehicles (FCEVs) are becoming increasingly popular due to their higher loading capacity, shorter charging times, and longer mileage compared to battery electric vehicles. However, increasing FCEV’s market competitiveness requires improving the efficiency of the cooling circulation system. In particular, in FCEV’s power electronics (PE) system, the coolant flow rate requires a very high discharge flow rate of more than 200 L/min, so the development of an electronic valve for flow control to manage this high flow rate is necessary. This study focuses on the computational fluid dynamics (CFD) flow analysis of valve designed to control high flow rates in electrical component cooling circulation system. Specifically, the flow resistance characteristics according to valve opening and flow conditions were analyzed. The results show that the design to minimize the interference area inside the valve can reduce the pressure drop somewhat. Furthermore, vertical flow path setting has been shown to be more effective than horizontal flow path setting. In addition to flow performance, design plans to expand the flow path diameter requires consideration from various perspectives. This research contributes to improving the efficiency of FCEVs and supports the market competitiveness of FCEVs as a promising eco-friendly alternative to traditional gasoline-powered vehicles