• 드라이브 ㆍ 컨트롤
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• 제19권4호
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• pp.97-103
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• 2022

Low fertility rates and increased life expectancy further exacerbate the process of an aging society. This is also reflected in the gradual increase in the proportion of vulnerable groups in the social population. The demand for improved mobility among vulnerable groups such as the elderly or the disabled has greatly driven the growth of the electric-assisted mobility device market. However, such mobile devices generally require a certain operating capability, which limits the range of vulnerable groups who can use the device and increases the cost of learning. Therefore, autonomous driving technology needs to be introduced to make mobility easier for a wider range of vulnerable groups to meet their needs of work and leisure in different environments. This study uses mini PC Odyssey, Velodyne Lidar VLP-16, electronic device and Linux-based ROS program to realize the functions of working environment recognition, simultaneous localization, map generation and navigation of electric powered mobile devices for vulnerable groups. This autonomous driving mobility device is expected to be of great help to the vulnerable who lack the immediate response in dangerous situations.

• Journal of Gastric Cancer
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• 제8권4호
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• pp.232-236
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• 2008

목적: 최근 조기 위암 환자를 대상으로 복강경 보조 위절제술이 널리 시행되고 있으며 경우에 따라서는 최선의 표준화된 수술방법으로 받아들여지고 있다. 이에 저자들은 조기 위암으로 진단된 329명의 환자를 대상으로 복강경 보조 원위절제술의 결과를 보고 하고자 하였다. 대상 및 방법: 2004년 4월부터 2006년 12월까지 서울아산병원에서 복강경 보조 위절제술을 받은 374예 중 원위절제술을 받은 329예를 학습곡선을 극복하는 시점을 기준으로 나누어 임상병리적 특성, 수술 소견, 수술 후 경과 및 합병증을 분석하였다. 결과: 329명의 환자 중 남자가 196명, 여자가 133명이었다. 평균 BMI는 23.6이고, 평균 수술 시간은 180.9분이며, 30예 이전은 287.9분이었고, 30예 이후는 170.2분으로, 30예 이후에 평균 수술 시간이 감소하였다(p<0.01). 림프절 절제는 30예 이전에는 D1절제가 5예(16.7%), D1+$\beta$이상이 25예(83.3%)였고, 30예 이후에는 D1절제가 16예(5.4%), D1+$\alpha$가 4예(1.3%), D1+$\beta$이상이 279예(93.3%)였다. 절제된 림프절의 개수는 22.7개, 30예 이전에는 18.6개, 30예 이후에는 23.1개로 30예 이후에 절제된 림프절의 개수가 많았다(P=0.02). 수술 후 평균 재원 기간은 $7.6\pm4.8$일이었으며, 30예 이전에는 9.3일, 30예 이후에는 7.4일로 30예 이후에 재원 기간이 줄어 들었다(P=0.04). 수술 전과 수술 후의 혈색소 차이는 평균 1.6 g/dl였고, 30예 이전에는 2.3 g/dl, 30예 이후에는 1.6 g/dl로 30예 이후 수술 중 출혈 양이 의미있는 감소를 보였다(P=0.02). 합병증은 출혈, 복강 내 농양, 문합부 누출, 문합부 협착, 수술 상처 감염, 폐렴 등 24예에서 나타났으며 30예 이전에는 3예, 30예 이후에는 21예에서 나타났다(P=0.45). 결론: 학습곡선의 극복 이후 수술시간이 단축되었고, 수술중 출혈양이 감소하였으며, 더 작은 절개창을 이용한 수술이 가능하게 되었다. 복강경 보조 원위절제술은 조기 위암 환자의 치료로 안전하게 시행될 수 있는 방법이라 생각한다.

• 대한음성학회:학술대회논문집
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• 대한음성학회 1997년도 7월 학술대회지
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• pp.176-178
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• 1997

To make a long story short I made up my mind to experiment with a multimedia approach to my classroom presentations two years ago because my ways of giving instructions bored the pants off me as well as my students. My favorite ways used to be sometimes referred to as classical or traditional ones, heavily dependent on the three elements: teacher's mouth, books, and chalk. Some call it the 'MBC method'. To top it off, I tried audio-visuals such as tape recorders, cassette players, VTR, pictures, and you name it, that could help improve my teaching method. And yet I have been unhappy about the results by a trial and error approach. I was determined to look for a better way that would ensure my satisfaction in the first place. What really turned me on was a multimedia CD ROM title, ELLIS (English Language Learning Instructional Systems) developed by Dr. Frank Otto. This is an integrated system of learning English based on advanced computer technology. Inspired by the utility and potential of such a multimedia system for regular classroom or lab instructions, I designed a simple but practical multimedia language learning laboratory in 1994 for the first time in Korea(perhaps for the first time in the world). It was high time that the conventional type of language laboratory(audio-passive) at Hahnnam be replaced because of wear and tear. Prior to this development, in 1991, I put a first CALL(Computer Assisted Language Learning) laboratory equipped with 35 personal computers(286), where students were encouraged to practise English typing, word processing and study English grammar, English vocabulary, and English composition. The first multimedia language learning laboratory was composed of 1) a multimedia personal computer(486DX2 then, now 586), 2) VGA multipliers that enable simultaneous viewing of the screen at control of the instructor, 3) an amplifIer, 4) loud speakers, 5)student monitors, 6) student tables to seat three students(a monitor for two students is more realistic, though), 7) student chairs, 8) an instructor table, and 9) cables. It was augmented later with an Internet hookup. The beauty of this type of multimedia language learning laboratory is the economy of furnishing and maintaining it. There is no need of darkening the facilities, which is a must when an LCD/beam projector is preferred in the laboratory. It is headset free, which proved to make students exasperated when worn more than- twenty minutes. In the previous semester I taught three different subjects: Freshman English Lab, English Phonetics, and Listening Comprehension Intermediate. I used CD ROM titles like ELLIS, Master Pronunciation, English Tripple Play Plus, English Arcade, Living Books, Q-Steps, English Discoveries, Compton's Encyclopedia. On the other hand, I managed to put all teaching materials into PowerPoint, where letters, photo, graphic, animation, audio, and video files are orderly stored in terms of slides. It takes time for me to prepare my teaching materials via PowerPoint, but it is a wonderful tool for the sake of presentations. And it is worth trying as long as I can entertain my students in such a way. Once everything is put into the computer, I feel relaxed and a bit excited watching my students enjoy my presentations. It appears to be great fun for students because they have never experienced this type of instruction. This is how I freed myself from having to manipulate a cassette tape player, VTR, and write on the board. The student monitors in front of them seem to help them concentrate on what they see, combined with what they hear. All I have to do is to simply click a mouse to give presentations and explanations, when necessary. I use a remote mouse, which prevents me from sitting at the instructor table. Instead, I can walk around in the room and enjoy freer interactions with students. Using this instrument, I can also have my students participate in the presentation. In particular, I invite my students to manipulate the computer using the remote mouse from the student's seat not from the instructor's seat. Every student appears to be fascinated with my multimedia approach to English teaching because of its unique nature as a new teaching tool as we face the 21st century. They all agree that the multimedia way is an interesting and fascinating way of learning to satisfy their needs. Above all, it helps lighten their drudgery in the classroom. They feel other subjects taught by other teachers should be treated in the same fashion. A multimedia approach to education is impossible without the advent of hi-tech computers, of which multi functions are integrated into a unified system, i.e., a personal computer. If you have computer-phobia, make quick friends with it; the sooner, the better. It can be a wonderful assistant to you. It is the Internet that I pay close attention to in conjunction with the multimedia approach to English education. Via e-mail system, I encourage my students to write to me in English. I encourage them to enjoy chatting with people all over the world. I also encourage them to visit the sites where they offer study courses in English conversation, vocabulary, idiomatic expressions, reading, and writing. I help them search any subject they want to via World Wide Web. Some day in the near future it will be the hub of learning for everybody. It will eventually free students from books, teachers, libraries, classrooms, and boredom. I will keep exploring better ways to give satisfying instructions to my students who deserve my entertainment.

• Korean Journal of Radiology
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• 제23권7호
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• pp.720-731
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• 2022

Objective: We aimed to develop and test a deep learning algorithm (DLA) for fully automated measurement of the volume and signal intensity (SI) of the liver and spleen using gadoxetic acid-enhanced hepatobiliary phase (HBP)-magnetic resonance imaging (MRI) and to evaluate the clinical utility of DLA-assisted assessment of functional liver capacity. Materials and Methods: The DLA was developed using HBP-MRI data from 1014 patients. Using an independent test dataset (110 internal and 90 external MRI data), the segmentation performance of the DLA was measured using the Dice similarity score (DSS), and the agreement between the DLA and the ground truth for the volume and SI measurements was assessed with a Bland-Altman 95% limit of agreement (LOA). In 276 separate patients (male:female, 191:85; mean age ± standard deviation, 40 ± 15 years) who underwent hepatic resection, we evaluated the correlations between various DLA-based MRI indices, including liver volume normalized by body surface area (LV_BSA), liver-to-spleen SI ratio (LSSR), MRI parameter-adjusted LSSR (aLSSR), LSSR × LV_BSA, and aLSSR × LV_BSA, and the indocyanine green retention rate at 15 minutes (ICG-R15), and determined the diagnostic performance of the DLA-based MRI indices to detect ICG-R15 ≥ 20%. Results: In the test dataset, the mean DSS was 0.977 for liver segmentation and 0.946 for spleen segmentation. The Bland-Altman 95% LOAs were 0.08% ± 3.70% for the liver volume, 0.20% ± 7.89% for the spleen volume, -0.02% ± 1.28% for the liver SI, and -0.01% ± 1.70% for the spleen SI. Among DLA-based MRI indices, aLSSR × LV_BSA showed the strongest correlation with ICG-R15 (r = -0.54, p < 0.001), with area under receiver operating characteristic curve of 0.932 (95% confidence interval, 0.895-0.959) to diagnose ICG-R15 ≥ 20%. Conclusion: Our DLA can accurately measure the volume and SI of the liver and spleen and may be useful for assessing functional liver capacity using gadoxetic acid-enhanced HBP-MRI.

• Korean Journal of Radiology
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• 제22권1호
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• pp.131-138
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• 2021

Objective: Iterative reconstruction degrades image quality. Thus, further advances in image reconstruction are necessary to overcome some limitations of this technique in low-dose computed tomography (LDCT) scan of the chest. Deep-learning image reconstruction (DLIR) is a new method used to reduce dose while maintaining image quality. The purposes of this study was to evaluate image quality and noise of LDCT scan images reconstructed with DLIR and compare with those of images reconstructed with the adaptive statistical iterative reconstruction-Veo at a level of 30% (ASiR-V 30%). Materials and Methods: This retrospective study included 58 patients who underwent LDCT scan for lung cancer screening. Datasets were reconstructed with ASiR-V 30% and DLIR at medium and high levels (DLIR-M and DLIR-H, respectively). The objective image signal and noise, which represented mean attenuation value and standard deviation in Hounsfield units for the lungs, mediastinum, liver, and background air, and subjective image contrast, image noise, and conspicuity of structures were evaluated. The differences between CT scan images subjected to ASiR-V 30%, DLIR-M, and DLIR-H were evaluated. Results: Based on the objective analysis, the image signals did not significantly differ among ASiR-V 30%, DLIR-M, and DLIR-H (p = 0.949, 0.737, 0.366, and 0.358 in the lungs, mediastinum, liver, and background air, respectively). However, the noise was significantly lower in DLIR-M and DLIR-H than in ASiR-V 30% (all p < 0.001). DLIR had higher signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) than ASiR-V 30% (p = 0.027, < 0.001, and < 0.001 in the SNR of the lungs, mediastinum, and liver, respectively; all p < 0.001 in the CNR). According to the subjective analysis, DLIR had higher image contrast and lower image noise than ASiR-V 30% (all p < 0.001). DLIR was superior to ASiR-V 30% in identifying the pulmonary arteries and veins, trachea and bronchi, lymph nodes, and pleura and pericardium (all p < 0.001). Conclusion: DLIR significantly reduced the image noise in chest LDCT scan images compared with ASiR-V 30% while maintaining superior image quality.

• 한국과학교육학회지
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• 제42권4호
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• pp.429-438
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• 2022

본 연구에서는 2015 개정 교육과정 지구과학 교과서를 중심으로 인포그래픽 유형을 분석하고 교사들의 그래픽 제작 도구 활용 실태를 점검함으로써 인포그래픽 제작 연수 프로그램을 통한 과학교사 전문성 신장 방안을 제안하고자 하였다. 이를 위해 지구과학 교과서에 제시된 시각화자료를 분석하여 인포그래픽의 유형에 따른 특징을 파악하였다. 또한, 인포그래픽 제작 연수 프로그램의 실행 결과를 유형별로 제시하고 연수 프로그램 이수 전후 설문 조사를 통해 과학교사들의 인포그래픽에 대한 인식 및 역량 변화를 분석하였다. 교과서 분석 결과 지구과학 교과에서는 도표형, 지도형, 비교분석형 인포그래픽을 가장 많이 사용하고 있으며, 주로 텍스트 보조형 인포그래픽으로 제시하였다. 과학교사 112명을 대상으로 인포그래픽 제작 연수프로그램을 5회 진행한 결과 완성형, 텍스트 보조형, 불완전형, 그레이디언트형 인포그래픽을 제작하였으며, 평가 문항 출제를 위한 불완전형 인포그래픽의 제작 수요가 가장 높았다. 설문 조사 결과에 따르면 대부분의 과학교사는 인포그래픽의 중요성을 인지하고 있으나, 인포그래픽을 제작해 본 경험이 없어 양질의 인포그래픽을 제작할 수 있는 역량이 부족한 것으로 나타났다. 연수 이수 후, 74.1%의 교사들이 수업자료와 평가 문항의 질이 향상되었다고 느꼈으며, 새로운 유형의 인포그래픽을 개발하는 과정이 전공 지식 재교육과 교수-학습방법 개선에 도움이 된다고 응답하였다. 연구 결과를 토대로 인포그래픽 제작 연수 프로그램을 통한 과학교사의 전문성 신장 방안을 제안하였다.

• Korean Journal of Radiology
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• 제24권3호
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• pp.259-270
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• 2023

Objective: It is unknown whether artificial intelligence-based computer-aided detection (AI-CAD) can enhance the accuracy of chest radiograph (CR) interpretation in real-world clinical practice. We aimed to compare the accuracy of CR interpretation assisted by AI-CAD to that of conventional interpretation in patients who presented to the emergency department (ED) with acute respiratory symptoms using a pragmatic randomized controlled trial. Materials and Methods: Patients who underwent CRs for acute respiratory symptoms at the ED of a tertiary referral institution were randomly assigned to intervention group (with assistance from an AI-CAD for CR interpretation) or control group (without AI assistance). Using a commercial AI-CAD system (Lunit INSIGHT CXR, version 2.0.2.0; Lunit Inc.). Other clinical practices were consistent with standard procedures. Sensitivity and false-positive rates of CR interpretation by duty trainee radiologists for identifying acute thoracic diseases were the primary and secondary outcomes, respectively. The reference standards for acute thoracic disease were established based on a review of the patient's medical record at least 30 days after the ED visit. Results: We randomly assigned 3576 participants to either the intervention group (1761 participants; mean age ± standard deviation, 65 ± 17 years; 978 males; acute thoracic disease in 472 participants) or the control group (1815 participants; 64 ± 17 years; 988 males; acute thoracic disease in 491 participants). The sensitivity (67.2% [317/472] in the intervention group vs. 66.0% [324/491] in the control group; odds ratio, 1.02 [95% confidence interval, 0.70-1.49]; P = 0.917) and false-positive rate (19.3% [249/1289] vs. 18.5% [245/1324]; odds ratio, 1.00 [95% confidence interval, 0.79-1.26]; P = 0.985) of CR interpretation by duty radiologists were not associated with the use of AI-CAD. Conclusion: AI-CAD did not improve the sensitivity and false-positive rate of CR interpretation for diagnosing acute thoracic disease in patients with acute respiratory symptoms who presented to the ED.

• 보건행정학회지
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• 제24권2호
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• pp.164-171
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• 2014

Background: Safety of drugs has become a major issue in public healthcare. Spontaneous reporting of adverse drug reaction (ADR) is the cornerstone in management of drug safety. We aimed to investigate the awareness and knowledge of spontaneous ADR reporting in general public of Korea. Methods: A total of 1,500 study subjects aged 19-69 years were interviewed with a questionnaire for their awareness and knowledge related to spontaneous ADR reporting. Computer assisted telephone interview was performed from 27th February 2013 to 4th March 2013. Target population was selected with quota sampling, using age, sex, and residence area. Healthcare professionals such as physicians, pharmacists, and nurses were excluded. The survey questions included awareness of spontaneous ADR reporting, opinions on ways to activate ADR reporting, and sociodemographic characteristics. Results: Overall awareness of spontaneous ADR reporting system was 8.3% (${\pm}2.53%$) among general population of Korea. Major source from which people got the information regarding ADR reporting was television/radio (69.9%), followed by internet (19.3%), and poster/brochure (6.1%). Awareness level differed between age groups (p<0.0001) and education levels (p<0.0001). Upon learning about the ADR reporting system, 88.5% of study subjects agreed on the necessity of ADR reporting system, while 46.6% thought promotion through internet and mass media as an effective way to activate ADR reporting. Conclusion: The overall awareness of spontaneous ADR reporting should be enhanced in order to establish a firm national system for drug safety. Adequate promotions should be performed targeting lower awareness groups, as well as various publicity activities via effective channels for the general population.

• Journal of Animal Science and Technology
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• 제56권4호
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• pp.15.1-15.10
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• 2014

Background: Morphologically classifying embryos is important for numerous laboratory techniques, which range from basic methods to methods for assisted reproduction. However, the standard method currently used for classification is subjective and depends on an embryologist's prior training. Thus, our work was aimed at developing software to classify morphological quality for blastocysts based on digital images. Methods: The developed methodology is suitable for the assistance of the embryologist on the task of analyzing blastocysts. The software uses artificial neural network techniques as a machine learning technique. These networks analyze both visual variables extracted from an image and biological features for an embryo. Results: After the training process the final accuracy of the system using this method was 95%. To aid the end-users in operating this system, we developed a graphical user interface that can be used to produce a quality assessment based on a previously trained artificial neural network. Conclusions: This process has a high potential for applicability because it can be adapted to additional species with greater economic appeal (human beings and cattle). Based on an objective assessment (without personal bias from the embryologist) and with high reproducibility between samples or different clinics and laboratories, this method will facilitate such classification in the future as an alternative practice for assessing embryo morphologies.

• 정보교육학회논문지
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• 제1권1호
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• pp.92-101
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• 1997

컴퓨터 환경 및 교육 환경의 변화에 따라서 하이퍼미디어 교육용 소프트웨어의 필요성이 증대되고 있으나, 대부분의 제작도구가 다양한 기능을 가지고 있음에도 불구하고 하이퍼미디어 프로그램 지원 지능이 부족하거나 사용법이 불편하다. 또, 제작된 프로그램에서의 새로운 노드의 생성 및 데이터의 추가는 불가능하여, 교수-학습 과정에서 발생하는 각종 학습 자료 및 정보를 누적할 수 없다는 문제점이 있다. 따라서 본 연구에서는 간편하게 하이퍼미디어 교육 자료를 제작하여 교수-학습에 활용할 수 있는 하이퍼미디어 자료 편집기의 모델을 제시하고자 하였다. CAI와 관련된 교수 학습 이론과 하이퍼텍스트 및 하이퍼미디어 관련 이론을 고찰하고, 국내 외의 제작도구의 특징을 분석하여, 편집 모드와 실행 모드가 함께 제공되는 하이퍼미디어 자료편집기를 설계 구현하였다. 본 자료편집기는 자료제시형의 교육용 소프트웨어를 제작 할 수 있도록 설계되었으므로 학생들의 조사 학습을 위한 데이터베이스 구축에 사용될 수 있으며, 사회과 등에서의 활발한 사용이 기대된다.