Phase Controllable Hyaluronic Acid Hydrogel with Iron(III) Ion–Catechol Induced Dual Cross-Linking by Utilizing the Gap of Gelation Kinetics

Lee, Jeongwook,Chang, Kyeol,Kim, Sunhye,Gite, Vikas,Chung, Hoeil,Sohn, Daewon American Chemical Society 2016 Macromolecules Vol.49 No.19

<P>Metal complexation-based gelation imparts load-bearing hydrogels with striking properties like reversibility, self-healing, and mechanical tunability. Using a bio-inspired metal catechol complex, these properties have been introduced to a variety of polymer hydrogels, except hyaluronic acid, which is widely used in biological applications. In this research, we developed two different hyaluronic acid (HA) hydrogels by regulating the gelation kinetics of Fe3+ and a catechol cross-linker, including Fe3+-induced covalent bonding and coordination bonding. Dual roles of Fe3+ in catechol-modified HA (HA-CA), Fe3+ catechol coordination, and catechol oxidation followed by a coupling reaction were selectively applied for different gelations. Phase-changeable HA-CA gel was attributed to dominant Fe3+ catechol coordination with immediate pH control. Alternatively, allowing a curing time to form catechol coupling bonds resulted in color-changeable HA-CA gels with pH control. The gel structure is then preserved by dual cross-linking through covalent catechol-coupling-based coordinate bonds and electrostatic interactions between Fe3+ and HA-CA. The hydrogels showed enhanced cohesiveness and shock-absorbing properties with increasing pH due to coordinate bonds inspired by marine mussel cuticles. The present gelation strategy is expected to expand the utility of HA hydrogels in biological applications, offering easy control over the phase, gel network, and visco elastic properties.</P>

Control of Culture Mediums on Hydroponic Growth of Ledebouriella Seseloides Seedlings under the Smart Greenhouse of Artificial Light Type

( Jeongwook Heo ),( Kyounghoon Park ),( Chanheum Park ),( Jaesu Lee ),( Jeonghyun Baek ),( Seouggil Hong ),( Gongin Lee ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

In hydroponic culture, several nutrient solutions were used for plant growth and development under smart greenhouse (Plant factory system) conditions with artificial lights instead of sun light. The conventional solutions are automatically irrigated for leafy plants production under controlled EC and pH conditions. Researches on the nutrient solution control were focused on the cool-season leafy plants such as lettuce spp. growing for 4~5 weeks after seedling transplantation on hydroponic culture bed. However, investigations on the effects of nutrient solutions for long term culture crops compared to the leafy plants have not been conducted. It was conducted to investigate the effect of conventional culture mediums on long-term growth of Ledebouriella seseloides seedlings under smart greenhouse conditions. Conventional Japan Wonsi standard (JW), Yamazaki Leaf lettuce (YL), and Yamazaki Padeudeuk (YP) solutions were used for hydroponic culture. The seedlings with a longer growth period than leafy plants were considered as a plant material. The seedlings which developed 2~3 true leaves were grown in the smart greenhouse with Light-Emitting Diodes (LEDs) lights of blue, red and white of 1:2:1 mixture in energy ratio. The three nutrient solutions were regularly irrigated by the deep flow technique (DFT) system on the culture gutters for 350 days. Long term culture of Ledebouriella seseloides seedlings with a longer growth period was established by the nutrient solutions which conventionally used for hydroponic culture of leafy plants inside the smart greenhouse conditions. There was no significance in the leaf growth of the seedlings such as fresh weight, leaf extension and leaf pigmentation among the mediums. From the results, it is suggested that the type of culture mediums was not crucial factor in long-term growth of the seedlings under controlled environments such as smart greenhouse conditions although average leaf number of the seedlings grown under MJ or YP treatment significantly increased.

Selective Analysis of Thiol-Containing Molecules Using Nanoengineered Micro Gold Shells and LDI-TOF MS

Jeongwook Lee,Juhee Lee,Hongseok Oh,목혜정,여운석 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.9

Study on the Natural Light Condensing and Transmission Device for Smart Farm

( Jaesu Lee ),( Youngsin Hong ),( Pyoungwoo Yang ),( Jeonghyun Baek ),( Jiseob Lim ),( Jongwon Park ),( Hyundong Lee ),( Jeongwook Heo ),( Hyunhwan Kim ),( Gookhwan Kim ),( Kilsu Han ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Smart farm (plant factory) technology is evolving into various farms of convergence technology through linkage with bio & IT industry, and urban agriculture. Particularly, it can serve as a key solution to societal issues, such as rural aging, rural migration settlement and rural job creation for young people. However, the level of technology and industrialization of the plant factories in domestic smart farms is still growing. For example, plant factories are centered on production of leaf vegetables due to limited technology to maintain light quality and intensity of artificial light sources. Therefore, it is important to acquire core technology necessary to design an automated system that enhances modeling and industrializing Korean smart farms. In this study, a natural light condensing and transmission device was designed to develop a next-generation light supply system that uses both natural and artificial light. The prototype of the natural light condensing and transmission device consisted of a condenser lens, an optical sensor, a light source tracking device, and an optical fiber. The condenser lens has increased the efficiency of the optical fiber by focusing more natural light on the optical fiber in the form of an aspherical convex lens. The optical sensor maximizes the efficiency of light collection by sensing from the sunrise. The light source tracking device enables more precise tracking of light sources as it uses an optical sensor system. The optical fiber has the highest degree of freedom among optical transmission technologies and it can transmit more than 200 m light sources with a low attenuation rate (0.06%/m). In the future, The spectroscopic measurement of light source and light efficiency (loss rate) will test using a spectrophotometer (FieldSpec 4, ASD Inc., USA) having a measurement range of 350 ~ 2,500 nm.

OpenCV를 이용한 빙 두께 영상처리 정확도 향상

이정욱(Jeongwook Lee),김희찬(Huichan Kim),박선호(Sunho Park) 한국해양환경·에너지학회 2021 한국해양환경·에너지학회 학술대회논문집 Vol.2021 No.10

본 연구에서는 선박의 쇄빙시 영상데이터를 이용하여 빙 두께를 측정하였다. C++를 이용하여 OpenCV에서 제공하는 영상처리 함수들을 호출하여 프로그램을 구성하였다. 영상처리 함수들을 이용하여 이미지를 보정하고 쇄빙되는 빙의 아래 경계선과 위 경계선을 Moore-Neighborhood 알고리즘을 이용하여 추출하였다. 개발한 프로그램은 Visual Studio의 MFC 라이브러리를 이용하여 가시화하였다. 이진화 과정에서의 원본 이미지와 라플라스 변환된 이미지의 비율을 조절하여 빙 두께 측정의 인식률과 정확도의 영향을 검토하였다. 또한, 데이터의 타입을 변화시켜 정확도를 향상시켰다. Ice thickness has been measured by ice breaking images of a ship. Ice thickness measuring program was developed by C++ language with OpenCV libraries. Ice thickness was measured using the Moore-Neighborhood algorithm, which extracted the ice upper and lower boundaries. The developed program was visualized using MFC library. In binary processing, the recognition and accuracy of ice thickness were improved by changing the ratio of original and Laplace transformed images. Also, the accuracy was improved by change the data type.

Revalidation of Safety Shutdown Earthquake Criteria for the Combustible Radioactive Waste Treatment Facility (CRWTF) Site

Jun Lee,Jeongwook Moon,Hee-Chul Eun 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

In light of recent significant seismic events in Korea and worldwide, there is an urgent need to reevaluate the adequacy of seismic assessments conducted during facility construction. This study reexamines the ongoing viability of the Safety Shutdown Earthquake (SSE) criteria assessment for the Combustible Radioactive Waste Treatment Facility (CRWTF) site at the Korea Atomic Energy Research Institute (KAERI), originally established in 1994. To validate the SSE assessment, we delineated 13 seismic structure zones within the Korean Peninsula and employed two distinct methodologies. Initially, we updated earthquake occurrence data from 1994 to the present year (2023) to assess changes in the site’s horizontal maximum earthquake acceleration (g). Subsequently, we conducted a comparative analysis using the same dataset, contrasting the outcomes derived from the existing distance attenuation equation with those from the most recent attenuation equations to evaluate the reliability of the applied attenuation model. The Safety Shutdown Earthquake (SSE) criterion of 0.2 g remains unexceeded, even when considering recent earthquake events since the original evaluation in 1994. Furthermore, when applying various assessment equations developed subsequently, the maximum value obtained from the previously utilized ‘Donvan and Bornstein’ attenuation equation is 0.1496 g, closely resembling the outcome derived from the recently employed ‘Lee’ reduction equation of 0.1451 g. The SSE criteria for CRWTF remain valid in the current context, even in light of recent seismic occurrences such as the 2016 Gyeongju earthquake. Additionally, the attenuation equation employed in the evaluation consistently yields conservative results when compared to methodologies used in recent assessments. Consequently, the existing SSE criteria remain valid at present. This study is expected to serve as a valuable reference for confirming the SSE criterion assessment of similarly constructed facilities within KAERI.

Development of auto-tuning shift-pattern in Auto-cruise vehicles

Hyunsub Lee,Changwoo Shin,Wonsik Lim,Sukwon Cha,Yongdal Lee,Jeongwook Kim 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

In order to adopt appropriate shift pattern to object vehicle, shift patterns should be revised by various road environment. However, too much time and money is spent in utilizing handmade procedure. The objective of this study is to develop the method which automatically can make base patterns and tuned patterns and to prove some advantages.

Operation of Radioactive Waste Management System

Jun Lee,Jeongwook Moon,Dong-Ju Lee,Dong-Su Kim,Hee-Chul Eun 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

KAERI has developed a Radioactive Waste Information Management System (RAWINGS) to manage the life-cycle information from the generation to the disposal of radioactive waste, in compliance with the low- and medium-level radioactive waste acceptance criteria (WAC). In the radioactive waste management process, the preceding steps are to receive waste history from the waste generators. This includes an application for a specified container with a QR label, pre-inspection, and management request. Next, the succeeding steps consist of repackaging, treatment, characterization, and evaluating the suitability of disposal, for a process to transparently manage radioactive wastes. Since the system operated in 2021, The system is enhanced to manage dynamic information, including the tracking of the location of radioactive waste and the repackaging process. Small packages of waste could be classified as either radioactive or clearance waste during pre-inspection. Furthermore, waste generated in the past has already been packaged in drums, and a new algorithm has been developed to apply the repackaging when reclassification is required. All radioactive waste with the unique ID number on the specific container is managed within a database, the total amount and history of waste are managed, and statistical information is provided. This system is continuously be operated and developed to oversee life-cycle information, and serve as the foundational database for the Waste Certification Program (WCP).

XR 콘텐츠 UI/UX 평가를 위한 VR 스마트 팩토리 교육훈련 콘텐츠 제작

이영우(YoungWoo Lee),임익수(EekSu Leem),이수민(Su Min LEE),김현식(Hyun Sik Kim),강민구(Mingoo Kang),이창교(Chang-kyo Lee),서정욱(Jeongwook Seo) 한국정보통신학회 2021 한국정보통신학회 종합학술대회 논문집 Vol.25 No.2

이 논문에서는 제조 분야에 디지털 트윈 기반 XR 콘텐츠의 UX/UI 디자인 및 사용성 평가를 위하여 범용적인 콘텐츠 소프트웨어와 달리, HDM의 의존성이 큰 XR 콘텐츠의 특성을 반영하기 위해, 공정수행작업 시나리오에 맞춘 XR 콘텐츠를 제작하였다. XR 콘텐츠의 공정수행 작업 시나리오를 수행하기 위해 Qculus Quest2라는 HMD장비를 사용하였으며, 콘텐츠 제작은 Unity 엔진[1]과 SteamVR Plugin을 통해 제작되었다. In this paper, VR smart factory XR content tailored to process execution scenarios was produced to reflect the characteristics of XR content, which is highly dependent on HDM, unlike general-purpose content software for UX/UI design and usability evaluation of digital twin-based XR content in manufacturing. HMD equipment called Qculus Quest2 was used to perform the process execution task scenario for XR content, and content production was made through Unity Engine and Steam VR Plugin.

스테레오 비전 및 객체 검출기를 이용한 작물 생장 진단 시스템 설계

이재수(Jaesu Lee),홍영신(Youngsin Hong),이상규(Sanggyu Lee),백정현(Jeonghyun Baek),김태현(Taehyun Kim),허정욱(Jeongwook Heo),노시영(Siyoung Rho),최인찬(Inchan Choi),곽강수(Kangsu Kwak),김현종(Hyunjong Kim) 한국원예학회 2020 한국원예학회 학술발표요지 Vol.2020 No.11