근적외선 분광분석법 이용한 출수기 후 벼의 함수율 예측 딥러닝 모델 개발

김남욱 ( Nam-wook Kim ),이홍구 ( Hong-gu Lee ),양하은 ( Ha-eun Yang ),김상은 ( Sang-eun Kim ),상완규 ( Wan-gyu Sang ),백재경 ( Jae-kyeong Baek ),모창연 ( Changyeun Mo ) 한국농업기계학회 2022 한국농업기계학회 학술발표논문집 Vol.27 No.2

국내 주요 작물로서 많은 양이 생산 및 소비되는 벼는 디지털 농업 기술의 선도적 적용을 통한 고도화가 유망한 작물 중 하나이다. 벼의 수분함량은 생산, 수확, 수확후 과정에서 식미, 품질 변화, 도정 효율 등 벼의 상품성 및 생산성에 큰 영향을 미치는 중요한 요소이다. 이를 향상시키기 위해 종자에 손상을 가하지 않음과 동시에 신속하고 정확한 수분함량 측정을 통한 적절한 농업 의사결정 및 수확 후 관리가 요구된다. 따라서 본 연구에서는 근적외선 분광분석법을 이용하여 도정 전 벼 함수율을 비파괴적으로 예측할 수 있는 딥러닝 모델을 개발하였다. 시료로 2022년 국립식량과학원에서 추수된 도정 전 상태의 신동진 벼가 사용되었으며, 출수기 후 14일, 21일, 28일, 35일, 42일이 지난 벼 종자를 획득하여 사용하였다. 각각의 그룹을 직경 50mm, 높이 15mm의 시료 용기에 담아 75개씩 샘플을 제작하여 샘플별 10회 분광 측정하였으며, 스펙트럼 측정 후 자연 건조를 통해 함수율 변화에 따른 스펙트럼을 추가적으로 측정하였다. 측정된 데이터들은 스펙트럼 전처리를 적용하여 학습 및 검증 데이터로 사용하였으며, 이후 인공신경망 네트워크를 개발하고 학습시켜 출수기 이후 벼 내부의 함수율 예측하는 딥러닝 모델을 개발하였다. 그 결과 근적외선 분광 기술과 딥러닝 알고리즘을 접목함으로서 벼의 함수율 측정이 가능함을 보였다. 또한 수확 벼의 물성 데이터 획득부터 함수율 예측까지의 과정을 비파괴적으로 신속하고 수행할 수 있는 방법을 제시하였다. 추후 벼 품질 결정 중요 인자들에 관한 연구들과 함께 활용되어 콤바인 기반 실시간 데이터 취득 및 품질 판정 시스템 연구 및 개발에 대한 기초 자료로 활용 가능할 것으로 판단된다.

Metal-free, polyether-mediated H₂-release from ammonia borane: roles of hydrogen bonding interactions in promoting dehydrogenation

Kim, Yongmin,Baek, Hyunjae,Lee, Jin Hee,Yeo, Shinyoung,Kim, Kibum,Hwang, Son-Jong,Eun, Bit,Nam, Suk Woo,Lim, Tae-Hoon,Yoon, Chang Won The Royal Society of Chemistry 2013 Physical chemistry chemical physics Vol.15 No.45

<P>Polyetheral additives were found to be efficient promoters to enhance the rate of H<SUB>2</SUB>-release from ammonia borane (AB) at various temperatures. In particular, tetraethylene glycol dimethyl ether (T4EGDE, 29 wt% relative to AB + T4EGDE) exhibited significantly improved activities for AB dehydrogenation, with the material-based hydrogen storage capacity of 10.3 wt% at 125 °C within 40 min. <I>In situ</I> FT-IR spectroscopy indicated the formation of B-(cyclodiborazanyl)amino-borohydride (BCDB), borazine, and μ-aminodiborane as gaseous byproducts. In addition, <SUP>11</SUP>B nuclear magnetic resonance (NMR) spectroscopy further revealed that diammoniate of diborane (DADB) was initially formed to give polyaminoborane as liquid and/or solid spent-fuel, consistent with previous reports. Density Functional Theory (DFT) calculations suggested that hydrogen bonding interactions between AB and a polyetheral promoter initially played an important role in increasing the reactivity of B–H bonds of AB by transferring electron density from oxygen atoms of the promoter into B–H bonds of AB. These partially activated, hydridic B–H bonds were proposed to help promote the formation of diammoniate of diborane (DADB), which is considered as a reactive intermediate, eventually enhancing the rate of H<SUB>2</SUB>-release from AB. In addition, our <I>in situ</I> solid state <SUP>11</SUP>B magic angle spinning (MAS) NMR measurements further confirmed that the rate of DADB formation from AB with a small quantity of T4EGDE was found to be much faster than that of pristine AB even at 50 °C. This metal-free method for H<SUB>2</SUB>-release from AB with an added, small quantity of polyethers would be helpful to develop feasible hydrogen storage systems for long-term fuel cell applications.</P> <P>Graphic Abstract</P><P>A metal-free method for H<SUB>2</SUB>-release from AB with addition of polyethers would be helpful to develop feasible hydrogen storage systems. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3cp52591k'> </P>

An Online-Applicable Model for Predicting Health Degradation of PEM Fuel Cells With Root Cause Analysis

Kim, Taejin,Oh, Hyunseok,Kim, Hyunjae,Youn, Byeng D. Institute of Electrical and Electronics Engineers 2016 IEEE transactions on industrial electronics Vol.63 No.11

<P>This paper proposes a new prognostic method for the health state of proton exchange membrane (PEM) fuel cells. The method is designed to predict the state-of-health (SOH) of PEMs and provide root cause analysis of the predicted health degradation. In this method, an equivalent circuit model (ECM) is built to emulate the impedance spectrum of PEM fuel cells. Because the key degradation parameters in the ECM cannot be measured in situ, this method instead estimates the parameters indirectly using the output voltage. The estimation is based on the linear relationship between the key ECM parameters and the output voltage. Using the constructed ECM and the estimated parameters, an impedance spectrum at the current moment is produced. The historical voltage evolution is then extrapolated using linear and exponential models that represent the irreversible and reversible phenomena, respectively. The models are used to predict future ECM parameters and, eventually, the impedance spectrum at any moment in the future. Through these steps, the proposed method provides an online estimation of the current SOH and predicts the level of future degradation. The primary novel feature of the proposed method is its ability to diagnose the root causes of potential degradation using data from nondisruptive online monitoring.</P>

An Artificial Intelligence Model Utilizing Computed Tomography Auto-Segmentation to Predict Hepatocellular Carcinoma in Patients with Chronic Hepatitis B

( Hyunjae Shin ),( Moon Haeng Hur ),( Seung Up Kim ),( Dong Hyun Sinn ),( Soo Young Park ),( Gi-ae Kim ),( Gwang Hyun Choi ),( Hwi Young Kim ),( Hyung-chul Lee ),( Yoon Jun Kim ),( Jung-hwan Yoon ),( 대한간학회 2024 춘·추계 학술대회 (The Liver Week) Vol.2024 No.1

Simultaneous Hard Tissue and Soft Tissue Graft with Dental Implant Placement and Provisionalization: A Case Report

Hyunjae Kim,Young-Dan Cho,Sungtae Kim Korean Academy of Dental Science 2024 Journal of korean dental science Vol.17 No.2

Achieving both esthetic and functional implant rehabilitation is crucial for the successful treatment of the anterior maxilla. Adequate peri-implant alveolar bone and soft tissue are essential for optimal rehabilitation of the esthetic area, and there is a direct association between the implant position and prosthetic outcomes. Immediate provisionalization may also be advantageous when combined with augmentation. This case report described the implant placement in a 25-year-old female patient who had lost her right maxillary lateral incisor (#12) due to trauma-induced avulsion. The treatment involved simultaneous grafting and collagenated, deproteinized bovine bone mineral, along with subepithelial connective tissue taken from the right maxillary tuberosity. A polyetheretherketone abutment and non-functional immediate provisionalization were performed by removing both the proximal and occlusal contacts on the composite resin crown. Clinical and radiographic evaluations revealed maintenance of stable ridge contour aspects for six months following surgical treatment. In summary, implant rehabilitation in the esthetic zone can be successful using simultaneous soft and hard tissue grafts. Moreover, soft tissue stabilization post-subepithelial connective tissue grafting can be achieved through early or immediate visualization, along with immediate implant placement.

Improvement in policy and proactive interconnection procedure for renewable energy expansion in South Korea

Kim, Sehyun,Lee, Hyunjae,Kim, Heejin,Jang, Dong-Hwan,Kim, Hyun-Jin,Hur, Jin,Cho, Yoon-Sung,Hur, Kyeon Elsevier 2018 RENEWABLE & SUSTAINABLE ENERGY REVIEWS Vol.98 No.-

<P><B>Abstract</B></P> <P>This paper presents the steps taken by the Korea Electric Power Corporation (KEPCO), the nation's only utility, to overcome limitations involved in increasing renewable energy penetration in an effort to support the government's movement for renewable energy expansion. While the government proposes reducing carbon dioxide emissions by 37% of the Business As Usual (BAU) value by 2030, which is about 315 million tonnes, it has improved energy policies for developing and deploying renewable energy technologies. To facilitate the integration of renewable energy into the future Korean power system, the government has announced a guaranteed interconnection policy for renewable energy sources under 1 MW. Based on this movement, the following measures have been enacted. First, examination of the hosting capacity of the current power system has been initiated to streamline the interconnection process for the distributed renewable energy sources and to reinforce the transmission and distribution network in a proactive manner. Second, to comply with reliability performance standards, an efficient planning procedure has been established for determining the optimal location and size of a renewable complex. To proceed with interconnection requests without delay, a prototype of a Renewable Energy Map (REM) based on PSS/e and Python has been developed. This tool facilitates more practical impact studies by incorporating capacity factors of renewable sources. In addition, it automates the screening process for determining suitable interconnection buses and feasible options for grid reinforcement. This tool is a step toward realizing the twin visions of “G-Platform” and “Carbon Zero” projects in Jeju Island.” These efforts, which have been initiated in response to the Paris Climate Change Accord of 2015 and the 23rd Conference of the Parties 2017, aim to increase renewable energy from 7% to 20% of the total generated energy in Korea by 2030.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The movement of the Korea government in improving support policy, interconnection procedure, and investments for renewable energy expansion. </LI> <LI> The movement of Korea Electric Power Corporation (KEPCO) in fully understanding current hosting capacity of the power system for enabling ‘Guaranteed interconnection of renewable energy sources under 1 MW’. </LI> <LI> The movement of KEPCO and associated universities for developing renewable energy map (REM) for establishing foundation of predicting efficient installation of renewable energy aggregation without violating reliability standard. </LI> <LI> Current projects regarding renewable energy expansion. </LI> </UL> </P>

A Multiple Guard Interval Based Frequency Error Detector for Carrier Frequency Synchronization in OFDM Systems

Hyunjae Kim(김현재),Hongku Kang(강홍구),Wooncheol Hwang(황운철),Kiseon Kim(김기선) 한국통신학회 2000 한국통신학회 학술대회 및 강연회 Vol.2000 No.5

Analysis of Research Trends in South Korean ODA for Ethiopia (2000-2015)

Kim HyunJae,Shon Mi,Kim YoungHwan,Park MinKyoung APEC국제교육협력원 2015 Asia-Pacific Cybereducation Journal Vol.11 No.2

The purpose of this study is to analyze the research trends in the South Korean Official Development Assistance (ODA), by examining the papers of degree thesis papers, project reports, and academic journals published from 2000 to 2015, as well as investigating and proposing the themes for future studies. According to the rubrics of analysis, from numerous papers, twelve thesis, twelve reports and eight academic journals were selected and considered following five analysis criteria; namely, published year, stakeholder of study, project procedure, methodology, and relevance to MDGs, the Millennium Development Goals. The results of the analysis are as follows: first, the papers associated with South Korean ODA for Ethiopia were published in 2008 for the first time. With steadily increasing numbers of thesis, reports, and journals, following after 2008, researches have conducted studies vigorously since 2011. However, investigations on the South Korean ODA for Ethiopia are noticeably insufficient, in comparison to the grant aids and concessional loans paid thus far. Secondly, the analysis appeared in twelve papers published by universities, eleven by government authorities, and eight by specialty magazines. Upon closer inspection, the government authority indicated Korea International Cooperation Agency (KOICA), and eight other specialty magazines, as well as the following: Korea Water Resources Association2), Korean Association of African Studies3), Korea Society of Agricultural Extension4), Korean Journal of Health Education and Promotion5), Journal of International Collaboration in Education6), Korea Research Society for Customs7),Perspectives in Nursing Science, The Women’s Studies8). Third, project procedure utilized as the criteria for the analysis. As a result, one feasibility study conducted in 2012 and 2013, one planning study in 2008 and 2010, two planning studies in 2013, one evaluation study in 2011 were identified. However, each project procedure paper for the 25 projects launched thus far were difficult to find. Papers for those have no relevance with ODA projects, and were considered as other studies. Fourth, papers relevant to the MDGs stand as such; 11 papers were linked with MDG 2, ‘Achieve universal primary education’. Three papers had relevance to MDG 1, ‘Eradicate extreme poverty and hunger’, one to MDG 3, ‘Promote gender equality’, three to MDG 5, ‘Improve maternal health’, four to MDG 6, ‘Combat HIV/AIDS malaria, and other diseases’, two to MDG 7, ‘Ensure environmental sustainability’, seven to MDG 8, ‘Develop a global partnership for development’. There were no papers connected with MDG 4, ‘Reduce child mortality’. Therefore, based on this trend analysis, broader spectrums and diverse methods of study should be implemented for the future studies with regard to the South Korean ODA for Ethiopia.

Sizing by Weighing: Characterizing Sizes of Ultrasmall-Sized Iron Oxide Nanocrystals Using MALDI-TOF Mass Spectrometry

Kim, Byung Hyo,Shin, Kwangsoo,Kwon, Soon Gu,Jang, Youngjin,Lee, Hyun-Seok,Lee, Hyunjae,Jun, Samuel Woojoo,Lee, Jisoo,Han, Sang Yun,Yim, Yong-Hyeon,Kim, Dae-Hyeong,Hyeon, Taeghwan American Chemical Society 2013 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.135 No.7

<P>We present a rapid and reliable method for determining the sizes and size distributions of <5 nm-sized iron oxide nanocrystals (NCs) using matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS). MS data were readily converted to size information using a simple equation. The size distribution obtained from the mass spectrum is well-matched with the data from transmission electron microscopy, which requires long and tedious analysis work. The size distribution obtained from the mass spectrum is highly resolved and can detect size differences of only a few angstroms. We used this MS-based technique to investigate the formation of iron oxide NCs, which is not easy to monitor with other methods. From ex situ measurements, we observed the transition from molecular precursors to clusters and then finally to NCs.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2013/jacsat.2013.135.issue-7/ja310030c/production/images/medium/ja-2012-10030c_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja310030c'>ACS Electronic Supporting Info</A></P>

Passive LED Driver Compatible with Rapid-Start Ballast

Hyunjae Kim,Byunghun Lee,Chun-Taek Rim 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

A new LED fluorescent driver compatible with a rapid-start ballast is proposed. Using a compensation circuit composed of passive elements, a new LED fluorescent driver having highly reliable and robust characteristics was developed. This driver can prevent the fire problem that arose in conventional LED fluorescent switching power supplies. The design principle and architecture of the proposed LED driver was explained, and its feasibility was confirmed by simulations and experiments.