State-of-the-Art Strategies for the Vascularization of Three-Dimensional Engineered Organs

Sangil Min,In Kap Ko,James J. Yoo 대한혈관외과학회 2019 Vascular Specialist International Vol.35 No.2

Engineering three-dimensional (3D) implantable tissue constructs is a promising strategy for replacing damaged or diseased tissues and organs with functional replacements. However, the efficient vascularization of new 3D organs is a major scientific and technical challenge since large tissue constructs or organs require a constant blood supply to survive in vivo. Current approaches to solving this problem generally fall into the following three major categories: (a) cell-based, (b) angiogenic factor-based, and (c) scaffold-based. In this review, we summarize stateof- the-art technologies that are used to develop complex, stable, and functional vasculature for engineered 3D tissue constructs and organs; additionally, we have suggested directions for future research.

Flat Pattern Peaks of Tacrolimus Absorption and Associated Pharmacogenomic Variants in Kidney Transplantation Recipients

Kim Suh Min,Lim Younggyun,Min Sangil,Min Byung-Joo,Seo Myung-Eui,Lee Kye Hwa,김주한,Ha Jongwon 대한의학회 2022 Journal of Korean medical science Vol.37 No.5

Background: Tacrolimus is the most commonly used immunosuppressive drug in solid organ transplantation. After administering a conventional twice-daily dose of tacrolimus, peak levels were achieved within the first 1.5 to 2 hours. A group of patients showed different early absorption phase of tacrolimus after kidney transplantation. Methods: Trough(C0) and 1.5-hour blood levels (C1.5) of tacrolimus were measured in 95 kidney transplantation recipients. Patients with a C1.5/C0 < 1.5 and > 1.5 were defined as those having flat pattern peaks and as controls, respectively. Transplantation outcomes were compared between the groups. Whole exome sequencing was performed to investigate the genetic susceptibility to flat pattern peaks. Results: Twenty-eight patients showed flat pattern peaks. The mean C1.5/C0 values were 1.13 ± 0.22 and 3.78 ± 1.25 in the flat pattern peak and control groups, respectively. In multivariate analysis, flat pattern peak was an independent risk factor for biopsy-proven acute rejection (BPAR) and/or borderline change (P = 0.014). Patients having flat pattern peaks showed significantly lower post-transplant 36-month estimated glomerular filtration rate (P = 0.001). Two single nucleotide variants in ABCB1 genes, rs1922242 and rs2235035, were associated with flat pattern peaks (P = 0.019 and P = 0.027, respectively). Conclusion: Both of C1.5 and C0 should be measured to distinguish the patients showing unique initial absorption. A C1.5/C0 ratio lower than 1.5 was associated with an increased risk of BPAR and/or borderline change. Single nucleotide variants s in ABCB1 gene might influence the flat pattern peaks of tacrolimus absorption.

THE USEFULNESS OF MORPHOLOGICAL CHARACTERISTICS AS A LONG-TERM MONITORING TOOL FOR CALCULATING INDIVIDUAL BIOMASS IN KELP SPECIES(Ecklonia cava)

Sangil Kim,Sun Kyeong Choi,Min Ji Kim,Eun Ran Baek,Seong Uk Hwang,Yun Hee Kang,Sang Rul Park 한국수산과학회 양식분과 2015 한국수산과학회 양식분과 학술대회 Vol.2015 No.5

어텐션 매커니즘 기반 심층 컨볼루션 뉴럴 네트워크를 사용한 산업용 불량 칩 검사

Min Je Kim,Altaf Hussain,Muhammad Munsif,Sangil Yoon,Mi Young Lee,Sung Wook Baik 한국차세대컴퓨팅학회 2023 한국차세대컴퓨팅학회 학술대회 Vol.2023 No.06

The identification of anomalies in industrial settings poses a significant challenge, especially when there is a lack of negative samples and when the anomalous regions are small. Although existing computer vision methods have automated this task to some extent, these approaches struggle to extract salient features for inspecting defective chips. To tackle this problem, a deep learning-based framework is proposed for detecting anomalies in industrial settings. The framework utilizes a fine-tuned backbone convolutional neural network model and incorporates an enhanced attention mechanism. The attention module generates discriminative feature maps along two dimensions: channel and spatial. This is achieved by processing intermediate features obtained from the backbone model. These attention maps are then multiplied with the input feature map to dynamically enhance the relevant features. Extensive experiments demonstrate the effectiveness of our proposed method in maintaining a high level of detection accuracy for industrial product inspections. Consequently, our results conclude a suitable solution for optical chip inspection systems in industrial settings.

박스 알고리즘을 활용한 새로운 암호화 방법

이상일(Sangil Lee),민승식(Seungsik Min) 한국정보기술학회 2017 한국정보기술학회논문지 Vol.15 No.11

Due to the invigorating of online activities, the number of the exposures of personal information is increasing each year, and the encryption technology is required to be improved every day. Interest in cryptography for the private field started in the 1970s, and DES, AES, and other cryptographic standards were developed. Although the complexity of these algorithms was considered to be very high, it turned out to be surprisingly easy to crack in the case of DES. Moreover, the safety of AES or SEED cannot be sustained. In this paper, we proposed a box algorithm as a Korean cryptographic algorithm and analyzed key length, complexity, and CPU time of the suggested algorithm. The box algorithm has a disadvantage in that the complexity is slightly smaller compared to the key length and the length of the ciphertext increases compared to the original text. Compared to other algorithms, however, it is easy to control the length of a key, which can increase the complexity to the desired level, and the ciphertexts are not unique. We analyzed the efficiency of the algorithm based on the key length, complexity, and CPU time and found an optimized value for the special cases.

FPGA 역공학 도구들의 실험적 검증 및 분석

이상일(Sangil Lee),이한솔(Hansol Lee),유호영(Hoyoung Yu),김영민(Youngmin Kim),이형민(Hyung-Min Lee) 대한전자공학회 2018 대한전자공학회 학술대회 Vol.2018 No.11

In this paper, we analyze the reverse engineering tools for FPGA devices and experimentally verify their performance and limitations. The paper introduces the design flow for Xilinx FPGAs with emphasis on Xilinx Design Language (XDL), XDL Report (XDLRC), and bitstream. Then, existing reverse engineering tools, which utilize the bitstream to recover the netlist, are analyzed with quantitative comparison of measured recovery rates.

Stump Length Changes after Endovenous Cyanoacrylate Closure or Radiofrequency Ablation for Saphenous Vein Incompetence

고현민,Sangil Min,Sanghyun Ahn,Ahram Han,Jungsun Kim,Seung-Kee Min 대한혈관외과학회 2021 Vascular Specialist International Vol.37 No.1

Purpose: The aim of this study was to analyze changes in stump length over time in patients with saphenous vein incompetence treated with cyanoacrylate closure (CAC) or radiofrequency ablation (RFA). Materials and Methods: We retrospectively analyzed data collected from patients with saphenous vein incompetence who underwent either CAC or RFA at Seoul National University Hospital between November 2015 and December 2018. The stump lengths were measured using duplex ultrasonography (DUS) within 1 month and 6 months after treatment. The Venous Clinical Severity Score (VCSS) and Aberdeen Varicose Vein Questionnaire (AVVQ) score were used to assess clinical outcomes. Results: A total of 97 veins (64 great saphenous veins and 33 small saphenous veins) were analyzed. The stump length was not significantly different between the two groups at <1 month (P=0.311). However, the stump length in the CAC group was significantly longer than that in the RFA group at 6 months (P=0.004). At 6 months, the mean change in stump length was 1.41±2.28 cm in the CAC group and 0.51±0.54 cm in the RFA group (P=0.006). The VCSSs and AVVQ scores significantly improved after both procedures but were not significantly different between the two groups. Conclusion: DUS at 6 months after treatment showed that the stump length in the CAC group increased more than that in the RFA group. No other factors affected the changes in stump length.

UAV 기반의 고랭지배추 주산단지 재배현황맵 활용방안

나상일 ( Sangil Na ),박찬원 ( Chanwon Park ),이경도 ( Kyoungdo Lee ),민병걸 ( Byoungkeol Min ),백신철 ( Shinchul Baek ),한중곤 ( Junggon Han ) 한국농공학회 2016 한국농공학회 학술대회초록집 Vol.2016 No.-

배추는 우리나라 국민들이 가장 많이 소비하는 채소 중 하나로서 출하되는 시기에 따라 월동배추(3~4월), 봄배추(5~6월), 여름배추(8월~9월), 가을배추(10월~11월)로 구분된다. 그 중 여름배추는 높은 온도와 습도로 인한 생리장해와 병해충으로 평지에서 재배하기 어려워 대부분 고랭지 지역 노지에서 재배되고 있어 고랭지배추라고도 한다. 고랭지는 해발고도가 높아질수록 기온이 점차 낮아지는 기후특성 때문에 포장재배 가능 기간이 짧다는 단점에도 불구하고 평난지에서 고온으로 재배가 어려운 각종 채소작물의 단경기 고품질 생산에 매우 중요한 역할을 맡고 있다. 그러나 최근 재배면적 감소와 기상이변으로 가격 변동이 커짐에 따라 고랭지배추 가격은 매년 사회적 관심사가 되고 있다. 이에 따라 농촌진흥청 국립농업과학원은 채소의 안정적인 공급을 위해 재배 면적 및 단수 예측이 필요하다고 판단하여 2015년부터 2018년까지 4년간 채소 작황과 관련된 연구에 무인비행체 영상을 적극적으로 활용하고 있다. 본 발표에서는 국립농업과학원의 연구 결과를 바탕으로 고랭지배추 주산단지 중 하나인 강원도 강릉시 안반덕의 재배현황맵 작성 현황 및 활용방안을 소개하고자 한다. 재배현황맵이란 무인항공기(UAV)로 촬영한 영상 분석 결과와 현장 표본조사 자료를 바탕으로 필지별 정식시기, 작물 분포, 생육 상황 등을 지도에 표시한 것으로 이를 통해 수확시기 추정, 재배면적 산정, 생육 이상 평가 등이 가능하다. 특히, UAV를 이용하여 촬영된 영상은 10cm 내외의 고공간해상도로 들녘 단위 재배단지의 필지별 생육상황 파악이 가능하고 기상이변 등에 따른 작황변화를 신속하게 판단할 수 있다. 또한, 주산지별로 정보가 축척되면 생산량 변동을 신속·정확하게 추정하여 채소 가격 안정화에도 기여할 수 있을 것으로 기대된다.

비트스트림 구조 분석을 통한 FPGA 식별 및 역공학 연구

이상일(Sangil Lee),유호영(Hoyoung Yu),조만희(Mannhee Cho),김영민(Youngmin Kim),이형민(Hyung-Min Lee) 대한전자공학회 2019 대한전자공학회 학술대회 Vol.2019 No.6

In this paper, we experimentally extracted the bitstream from FPGA devices and verified a part of bitstream information. The paper first introduces the design flow of Xilinx FPGAs with emphasis on Xilinx Design Language (XDL) and bitstream, and then explains how to identify the FPGA device from the extracted bitstream.

메뉴의 배열과 사용자 스크립트가 스마트폰 애플리케이션 과제 수행에 미치는 효과

민승기(Sungki Min),박수영(Soo-Young Park),이상일(Sangil Lee) 한국콘텐츠학회 2021 한국콘텐츠학회논문지 Vol.21 No.4

모바일 앱으로 과제를 수행할 때에 트리-뷰 메뉴의 외적인 구조에 따라 사용성이 달라지고, 메뉴의 배열이 사용자가 기대하는 스크립트와 다를 때에 사용성이 떨어지고, 그리고 과제의 복잡성에 따라 이 둘의 효과가 달라진다는 연구가설을 검증하였다. 이를 위하여 대학생 참가자들이 기대하는 숙박 예약 스크립트를 작성하였으며, 과제완료시간과 오반응률을 종속변인으로 하는 실험을 설계하였다. 실험은 예약 시스템 프로토타입을 스마트폰에 구현하여 실시하였다. 그 결과로 과제가 복잡할 때에 수행이 전반적으로 불리한 가운데, 구획메뉴의 수월성이 과제가 복잡할 때에 두드러졌으며 복잡한 과제에서 메뉴의 배열이 기대와 일치할 때에 긍정적인 반응이 관찰되었다. 이러한 결과를 논의하여 모바일 화면에 절차적인 메뉴를 설계할 때에는 작업기억의 부담을 최소화하는 방안을 마련하고, 과제에 맞는 트리-뷰가 무엇인지를 고민하고, 그리고 복잡한 과제에서는 사용자가 기대하는 스크립트에 준하여 메뉴를 배열하여야 한다는 사실을 발견할 수 있었다. Three research hypotheses expected when working with a mobile app were verified. As follows: (1) Usability varies depending on the external structure of the tree-view menu. (2) If the menu arrangement is different from the script expected by users, the usability is poor. And (3) the effects of each of these two hypotheses vary depending on the complexity of the task. To this end, a script for booking accommodations expected by undergraduate students was written, and an experiment was designed with the task completion time and error rate as dependent variables. The experiment was conducted by implementing a prototype for reservation system on a smartphone As a result, while the overall performance was unfavorable when the task was complicated, the superiority of sectional menu was prominent when the task was complicated, and positive responses were observed when the menu arrangement in a complicated task matched user expectations. By discussing these results, it was found that when designing a procedural menu on a mobile screen, we come up with measures to minimize the burden of working memory, consider what tree-views are for the task, and that in complex tasks, menus should be arranged according to the scripts expected by users.