전후대칭 구조의 4륜 조향 모바일 로봇 설계

박송은,서정욱 제어·로봇·시스템학회 2023 제어·로봇·시스템학회 논문지 Vol.29 No.9

Ackermann steering can reduce the turning radius of a vehicle to a limited extent, and individual steering for mobile robots increases cost owing to the need for more actuators. Therefore, in this paper, we propose a novel front-back-symmetric-steering mechanism that allows four-wheel steering using only two actuators. A robot prototype is fabricated to verify the basic performance of this design. The proposed steering system has no restriction on the change of the steering angle; therefore, the robot can rotate in place without lateral slip of the wheels. In addition, the four-wheel-drive function combined with the steering mechanism facilitates smooth driving even on somewhat uneven road surfaces without requiring a suspension system. As a result, the proposed steering mechanism is expected to apply to various mobile robots owing to its simplicity and the ability to achieve excellent rotation characteristics.

다지표 잠재성장모형에서 요인동일성과 요인척도 설정의 문제: 모형 적합도와 모수 추정값에 미치는 영향

박송이,장승민 한국심리학회 2018 한국심리학회지 일반 Vol.37 No.1

The multiple-indicator latent growth model (MI-LGM) is a second-order confirmatory factor model that analyzes latent trajectories of a factor measured by multiple indicators over time. Although MI-LGM can test the factorial invariance of indicators and estimate trajectories of a latent variable controlling measurement error, model fit and parameter estimates of the model may vary depending on factor scaling methods. The purpose of this study is to investigate how factor scaling methods, given a specified level of factorial invariance, change the meaning of the factor mean and thus affects the model fit and parameter estimates of MI-LGM. The authors first explored how factorial invariance and factor scaling affect the definition of factor means and the model fit in longitudinal factor analysis models. Next, they showed that constraining the sum of the indicator’ intercepts to zero creates a clear definition of the factor mean and the constraint provides consistent results and interpretation of the means of growth factors in the MI-LGM even under the weak factorial invariance. An analysis of actual panel data then illustrated such characteristics of the MI-LGM. Finally, the authors discussed the importance of factorial invariance and factor scaling in the analysis of mean and covariance structure models and that of using the strong factorial invariance when modeling the MI-LGM. 다지표 잠재성장모형(LGM)은 여러 관측변수에 의해 측정되는 요인의 시간에 따른 변화 궤적을 2차 요인모형을 이용하여 분석하는 모형이다. 다지표 LGM은 여러 가지 장점에도 불구하고 요인척도법에 따라 모형 적합도와 모수 추정값이 달라지는 문제를 가지고 있다. 본 연구는 다지표 LGM에서 요인동일성의 수준과 요인척도의 설정 방식에 따라 요인 평균의 의미가어떻게 달라지는지를 규명하고, 요인척도의 설정이 다지표 LGM의 모형 적합도와 모수 추정값에 어떻게 영향을 미치는지를 확인하였다. 먼저 종단 요인분석 모형에서 요인동일성 제약과 요인척도법에 따라 요인 평균이 어떻게 정의되는지와 모형 적합도가 어떻게 달라지는지논의하였다. 또한 절편의 합을 0으로 제약하는 설정이 요인 평균을 어떻게 정의하는지 밝히고, 이러한 제약이 약한 요인동일성을 가정한 다지표 LGM의 성장 요인 평균에 대해 일관적인 분석 결과와 해석을 제공한다는 것을 제시하였다. 이어서 패널 자료를 이용한 실제 자료의 분석을 통해 이와 같은 다지표 LGM의 특징을 예시하였다. 끝으로 평균공분산구조 모형의분석에서 요인동일성과 요인척도 설정의 중요성과 다지표 LGM에서 강한 요인동일성 모형을사용하는 것의 중요성에 대해 논의하였다.

유산

박송 문예운동사 1980 문예운동 Vol.- No.28

3D metal printing에 의한 이종금속 대형 조형물 제작 연구

박송이(Song-Yi Park),이채영(Chae-Young Lee),장단비(Dan-Bi Jang),김안나(An-Na Kim),김수현,문유빈(Yu-Bin Mun),정유진(Yu-Jin Joung),조상명(Sang-Myung Cho) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

3D metal printing(AM) technology is the production technology to create metal products in way that the melted metal deposit from 3D CAD model data directly. Recently, research of AM techniques is active. AM techniques are divided into powder-based AM and wire-based AM. Wire-based AM is good for AM products of large-scale with a high speed deposition, inexpensive material. When TIG welding which is one of wire-based AM is applied, TIG welding AM is possible to control respectively the speed of the filler wire and arc intensity. Also, TIG welding AM has the advantages of wire-based AM and of clean environment. This study was carried out to establish the bead shape and dominant parameter that are suitable for build-up. STS316L and Albronze(CuAl-A2) were built up using conventional TIG and the Super_TIG welding in order to apply to the AM. The heat input as build-up should be increased for getting a uniform bead shape, because Albronze has high thermal conductivity. The heat input for STS316L as build-up should be reduced in order to get a uniform bead shape, because it has thermal barrier effect due to low thermal conductivity. Applying the Super_TIG welding, the productivity was about 3times of conventional TIG welding. The uniform wall thickness and good appearance could be obtained even if STS316L and Albronze were built alternately.

Clinical performance of medical students in Korea in a whole-task emergency station in the objective structured clinical examination with a standardized patient complaining of palpitations

박송이,공현희,김민정,윤유상,이상화,임선주,서지현 한국보건의료인국가시험원 2020 보건의료교육평가 Vol.17 No.-

This study assessed the clinical performance of 150 third-year medicalstudents in Busan, Korea in a whole-task emergency objective structured clinical examination station that simulated a patient with palpitations visiting the emergency department. The examination was conducted from November 25 to 27, 2019. Clinical performance was assessed as the number and percentage of students who performed history-taking (HT), a physical examination (PE), an electrocardiography (ECG) study, patient education (Ed), and clinical reasoning (CR), which were items on the checklist. It was found that 18.0% of students checked the patient’s pulse, 51.3% completed an ECG study, and 57.9% explained the results to the patient. A sizable proportion (38.0%) of students did not even attempt an ECG study. In a whole-task emergency station, students showed good performance on HT and CR, but unsatisfactory results for PE, ECG study, and Ed. Clinical skills educational programs for subjected student should focus more on PE, timely diagnostic tests, and sufficient Ed.

3D 프린팅 된 서베이드 금관과 금속 프레임워크를 이용한 양악 가철성 의치 수복 증례

박송이,박상원,박찬,장우형,윤귀덕 대한치과보철학회 2023 대한치과보철학회지 Vol.61 No.2

Computer-aided design–computer-aided manufacturing technology has been widely used in the manufacture of fixed prostheses including implants, but in the case of removable dentures, the analog method is still being used due to the errors such as a lack of fusion and over-fusion in selective laser meting process. With the recent development of CAD software, virtual surveying and framework design are made possible, and the designed file can be manufactured by milling or 3D printing. It replace the analog method of waxing and denture curing process and also can reduce the production time and cost. Therefore, this case is reported because good clinical results were obtained by digitally surveying on CAD software to produce a surveyed metal restoration and framework on maxillary and mandibular removable dentures. 임플란트를 비롯한 고정성 보철물 제작에 있어서 Computer-aided design-computer-aided manufacturing 기술이 많이 사용되어 왔지만 가철성 의치의 경우 Selective laser melting 방식의 레이저 분말의 융합과정에서 오차가 생기면 융착 부족이나 과융합 등의 오차가 발생하여 정밀도를 크게 손상시킬 수 있어 여전히 기존의 아날로그 방식의 제조법을 사용하고 있다. 최근 CAD 소프트웨어의 발달로 가상의 서베잉과 프레임워크의 디자인이 가능해지고 이렇게 디자인된 형태를 밀링이나 3D 프린팅과 같은 방식으로 제작할 수 있게 되면서 전통적인 의치제작 방식 중 납형 제작이나 온성과 같은 과정을 대체할 수 있게 되었고, 제작 소요되는 시간과 비용을 줄일 수 있다. 따라서 본 증례는 CAD 소프트웨어 상에서 디지털 서베잉을 시행하여 서베이드 금속도재관을 제작하고 금속 프레임워크를 디자인하여 이를 3D 프린팅 하는 디지털 방식의 상하악 가철성 의치를 제작하여 좋은 임상 결과를 얻었기에 보고하는 바이다.

Exploring the experiences and perspectives of emergency physicians on brain death organ tissue donation after the Life-Sustaining Treatment Decision Act

박송이,김현,박귀화,박승민,이동언,Yong Hun Jung,정원준,박경혜 대한이식학회 2022 Korean Journal of Transplantation Vol.36 No.1

Background: This study explored emergency physicians’ experiences and perspectives related to brain death organ tissue donation (OTD) after the enforcement of the Life-Sustaining Treatment (LST) Decision Act in Korea. Methods: Using the Braun and Clarke thematic analysis method, this qualitative study analyzed interview data—comprising experiences and perspectives of brain death OTD since the LST Decision Act—of 10 emergency physicians who specialized in targeted temperature management (TTM) and cared for post-cardiac arrest patients. Results: Data analysis revealed 13 subthemes and 5 themes: the LST Decision Act is easier to explain to family members than brain death OTD, but it does not fit well in an emergency medical setting; many family members decide to stop LST even before physicians mention brain death or OTD; family members view stopping LST as being about comforting patients without bothering them, and decision-makers are therefore no longer willing to choose OTD; stopping LST does not always result in brain death, but cases of brain death are preceded by stopping LST; and since the LST Decision Act, the number of TTM cases and potential brain death donors has decreased. Conclusions: Unless a supplementary policy that connects stopping LST to brain death OTD is prepared, the withdrawal of LST in patients resuscitated after cardiac arrest is expected to continue, and brain death OTD is expected to decrease.

나의 시와 그 해설-청산 별곡

박송 문예운동사 1981 문예운동 Vol.- No.29

물방앗간 사연

박송 문예운동사 1981 문예운동 Vol.- No.30

산길을 가면

박송 문예운동사 1982 문예운동 Vol.- No.32