대장 및 직장손상의 임상적 고찰

김효곤,김정용,김성환 대한대장항문학회 1990 Annals of Coloproctolgy Vol.6 No.2

BERT를 활용한 미국 기업 공시에 대한 감성 분석 및 시각화

김효곤,유동희 한국정보시스템학회 2022 情報시스템硏究 Vol.31 No.3

Purpose This study quantified companies’ views on the COVID-19 pandemic with sentiment analysis of U.S. public companies’ disclosures. It aims to provide timely insights to shareholders, investors, and consumers by analyzing and visualizing sentiment changes over time as well as similarities and differences by industry. Design/methodology/approach From more than fifty thousand Form 10-K and Form 10-Q published between 2020 and 2021, we extracted over one million texts related to the COVID-19 pandemic. Using the FinBERT language model fine-tuned in the finance domain, we conducted sentiment analysis of the texts, and we quantified and classified the data into positive, negative, and neutral. In addition, we illustrated the analysis results using various visualization techniques for easy understanding of information. Findings The analysis results indicated that U.S. public companies’ overall sentiment changed over time as the COVID-19 pandemic progressed. Positive sentiment gradually increased, and negative sentiment tended to decrease over time, but there was no trend in neutral sentiment. When comparing sentiment by industry, the pattern of changes in the amount of positive and negative sentiment and time-series changes were similar in all industries, but differences among industries were shown in neutral sentiment.

굴곡건 섬유종에 의한 수근관증후군 및 완관절의 방아쇠 현상

김효곤,하성한,이기준,유선오,김정래 대한수부외과학회 2013 대한수부외과학회지 Vol.18 No.2

Triggering of the flexor tendon at the wrist is a rare phenomenon. The triggering can be caused by many different conditions, including anomalous muscle,thickened synovium, rheumatoid disease and tumors. We report the case of a 34-year-old man with triggering at the wrist and carpal tunnel syndrome caused by a fibroma of the flexor tendon. 완관절에서 굴곡건에 의한 방아쇠 현상은 매우 드물다. 원인은 매우 다양하여 종양이나 비정형적인 근육, 결절성 류마토이드질환, 굴곡건의 결절, 인대의 파열, 활액막의 비대 등이 완관절에서 방아쇠 현상을 유발한다. 저자는 34세 남자환자로 굴곡건 섬유종에 의해 발생한 수근관증후군과 완관절의 방아쇠 현상에 대한 증례를 보고하고자 한다.

무인수상정을 위한 경로선 추종이 가능한 개선된 Dynamic Window Approach

김효곤,윤성조,최영호,이정우,유재관,원병재,서진호,Kim, Hyogon,Yun, Sung-Jo,Choi, Young-Ho,Lee, Jung-Woo,Ryu, Jae-KWan,Won, Byong-Jae,Suh, Jin-Ho 대한임베디드공학회 2017 대한임베디드공학회논문지 Vol.12 No.5

Recently, autonomous navigation technology, obstacle recognition, and obstacle collision avoidance technology are actively being developed for an unmanned surface vehicle (USV). The path to move from the current location to the destination should be planned, in order for an USV to autonomously operate safely to its destination. The dynamic window approach (DWA) is a well-known navigation scheme as a local path planning. The DWA algorithm derives the linear velocity and angular velocity by evaluating the destination direction, velocity, and distance from the obstacle. However, because DWA algorithm does not consider tracking the path, when using only the DWA algorithm, the ship may navigate away from the path line after avoiding obstacles. In this paper, we propose an improved DWA algorithm that can follow path line. And we implemented the simulation and compared the existing DWA algorithm with the improved DWA algorithm proposed in this paper. As a result, it is confirmed that the proposed DWA algorithm follows the path line better.

Design of a novel knee joint for an exoskeleton with good energy efficiency for load-carrying augmentation

김효곤,박상덕,한창수 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.11

When a linear actuator is used for rotation motion by a knee joint of an exoskeleton, the specifications of the joint range of motion(ROM) and joint torque change according to how the linear actuator are attached. Moreover, while the linear actuator generates a constantamount of force, the joint torque generated by the actuator changes according to the joint angle, which causes the torque contraction. This makes it difficult to meet the required torque and ROM for walk and stand-to-sit and sit-to-stand (STS) motions while carrying aload. To solve these problems we propose a novel knee joint for an exoskeleton with good energy efficiency during walk and STS motionswhile carrying a load. The mechanism is composed of a four-bar linkage and an elastic element. Based on an analysis of humanmotion, the design variables of the joint were optimized and the feasibility of the optimized variables was verified through the simulation. The findings from the simulation results suggest that combining a four-bar linkage with a linear actuator allows a large ROM and goodtorque performance of the knee joint for walk and STS motions. Moreover, the energy efficiency can be improved because the springmounted parallel to the actuator can store the energy dissipated as negative work and recycle the energy as positive work.

Uncalcified Synovial Chondromatosis in the Pisotriquetral Joint

김효곤,하성한,이기준,유선오,김정래 대한정형외과학회 2015 Clinics in Orthopedic Surgery Vol.7 No.3

Synovial chondromatosis is a rare lesion in the wrist, but some cases in the distal radioulnar joint have been reported and previous case reports emphasize joint calcifications, shown on preoperative plain radiographs. We report an extremely uncommon case of synovial chondromatosis in the pisotriquetral joint, in which radiographs and magnetic resonance imaging did not demonstrate apparent calcified bodies. In our case, for the accurate diagnosis and treatment, surgical exploration of the joint and synovectomy with removal of loose bodies was performed.

Design of an Exoskeleton with Minimized Energy Consumption based on using Elastic and Dissipative Elements

김효곤,한창수,이정원,장재호,박상덕 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.2

This study proposes the design of an exoskeleton featuring minimized energy consumption during stand-to-sit and sit-to-stand (STS) motion and walking while carrying a load through the utilization of elastic and dissipative elements. In order to determine which phase and joint can utilize elastic and dissipative elements, we analyzed a human’s walk and STS motions. With this human motion data, we propose an elastic element for hip adduction and abduction (Ad/Ab), series dissipative actuation (SDA) using a semi-active hydraulic system for hip flexion and extension (Fl/Ex) and parallel elastic and series dissipative actuation (PESDA) for the knee Fl/Ex, which is combined with the SDA and the parallel elastic element. The effect of the developed exoskeleton (EXO) with a hip Ad/Ab spring, hip SDA and knee PESDA was evaluated by measuring the user’s ground reaction force (GRF). When wearing the EXO with a hip Ad/Ab spring, hip SDA and knee PESDA, the subject’s GRF was smaller as compared to when the subject was not wearing the EXO while walking and performing the STS motion under a 20-kg load condition, except during the heel strike of the walk motion.

김수영의 < 사랑의 변주곡 > 연구

김효곤 문창어문학회 1996 문창어문논집 Vol.33 No.-

김수영의 <사랑의 變奏曲> 연구 : 김수영의 <사랑의 변주곡> 연구

김효곤 釜山大學校 人文大學 國語國文學科 1996 國語國文學 Vol.33 No.1

A modified RIO for Improving Assured Service Performance

김효곤,Kim, Hyo-Gon 한국정보처리학회 1999 정보처리학회논문지 Vol.6 No.11

In this paper, we explore two ways to improve the bandwidth assurance performance of Assured Service(AS). It is well known that AS fails to meet the bandwidth assurance target for large-profile TCP flows competing with many small-profile flows. This flows after the back-offs induced by packet drops. Thus currently proposed solution to this problem naturally focus on modifying TCP's behavior to counter the unfairness in the TCP dynamics. Unfortunately, these proposals lack practicability in terms of the required changes in the incumbent Internet infrastructure. Admitting this difficulty, we instead look to not yet deployed Diff-Serv mechanisms for practical solutions. In particular, we investigate the role of RIO, RED with IN(in-profile) and OUT(out-profile), queue management scheme in the assurance failure for As. Specifically, we identify the inadequacy of RIO that aggravates the bandwidth assurance failure. Then we alleviates the bandwidth assurance failure problem by separately controlling the out-of-profile packet queue length. Through extensive simulations we demonstrate that RI+O extends the regime where AS consistently provides the bandwidth assurance.