가연성 냉매 누설 시나리오에 따른 언더후드 내부 유동 해석

이승연(Seungyeon Lee),최종민(Jongmin Choi),이대웅(Daewoong Lee),이해준(Haejun Lee),김민수(Min Soo Kim) 대한설비공학회 2021 대한설비공학회 학술발표대회논문집 Vol.2019 No.-

수치해석을 활용한 전기차 이차 루프 히트펌프 시스템의 R290 냉매 누설 시 안전성 평가

이승연(Seungyeon Lee),최종민(Jongmin Choi),이대웅(Daewoong Lee),이해준(Haejun Lee),김민수(Min Soo Kim) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

With increasing interest in environmental protection, the technologies related with electric vehicles are rapidly developing. Among them, heat pump technology is attracting attention as it can extend the mileage at winter, through efficient heating. On the other hand, the refrigerant applied to the heat pump system also needs to be more eco-friendly. One of the candidates, R290, has excellent thermal properties but also has high flammability of A3 grade. Although the secondary-loop heat pump system can block the flow of the refrigerant into the cabin in case of leakage, it is necessary to evaluate the risk of ignition in the underhood of the vehicle for safer operation. Therefore, we established a model to analyze the safety of R290 leakage of secondary-loop heat pump system for an electric vehicle, and investigated the effect of various driving conditions and leakage situations on the risk.

수소연료전지 버스의 비선형 모델 예측 제어를 활용한 실시간 동력 분배 제어 알고리즘

이승연(Seungyeon Lee),이주인(Jooin Lee),임종원(Jongwon Lim),이형철(Hyeongcheol Lee) 한국자동차공학회 2023 한국자동차공학회 학술대회 및 전시회 Vol.2023 No.11

In this paper, power distribution control algorithm for fuel cell electric bus was developed. Power distribution control algorithm is developed by using Gradient based Model Predictive Control(GRAMPC). Algorithm considered vehicle’s system characteristics like fuel cell, battery, motor and vehicle dynamics. Cost function is developed with considering battery’s State-of-charge and consumption ratio of fuel cell. GRAMPC can execute nonlinear model predictive control algorithm with real-time environment. Driving scenario is developed including real world traffic condition by using SUMO and Autonomie. Algorithms is validated in real-time simulation environment with dSPACE RCP-HIL simulator.

Evaluating User Experience Using Physiological Data from Conversational Interfaces for Interactive TV

Seungyeon Lee(이승연),Chan Hyeok Yun(윤찬혁),Gee Won Shin(신지원),Soo Yeon Kim(김수연),Myung Hwan Yun(윤명환) 대한인간공학회 2020 대한인간공학회 학술대회논문집 Vol.2020 No.6

Objective: This study aims to investigate TV viewers’ user experience (UX) of a conversational agent (CA) that assisted interactions while watching TV. Background: TV is evolving into an interactive product as technology advances, but the TV interface has not changed much. This can limit the UX of interactive TV viewers. Therefore, it is necessary to identify how the use of voice-interactive interface affects the TV users in order to have a better interactive TV experience. Method: To comparatively analyze the UX with the CA interface and the traditional remote control unit (RCU) interface, physiological measurements (skin conductance; SC) for objective data as well as self-report questionnaires were evaluated. Results: Physiological measurement results showed that SC differed between CA and RCU interactions. Most SC data were high at the beginning of the CA interaction but decreased over time. In RCU sessions, SC maintained a constant value or increased. Consequently, CA had a greater effect on the overall attractiveness while having more emotional appeal. Conclusion: Subjective results showed that CA provided a more positive TV experience regarding emotional aspects. Application: Physiological measurement can provide a more detailed and rich interpretation of the emotional changes and cognitive efforts during human-TV interaction, leading to better understanding of the UX meditated by interactive agent.

수치해석을 활용한 전기차 이차 루프 히트펌프 시스템의 R290 냉매 누설 시 안전성 평가

이승연(Seungyeon Lee),최종민(Jongmin Choi),이대웅(Daewoong Lee),이해준(Haejun Lee),김민수(Min Soo Kim) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

With increasing interest in environmental protection, the technologies related with electric vehicles are rapidly developing. Among them, heat pump technology is attracting attention as it can extend the mileage at winter, through efficient heating. On the other hand, the refrigerant applied to the heat pump system also needs to be more eco-friendly. One of the candidates, R290, has excellent thermal properties but also has high flammability of A3 grade. Although the secondary-loop heat pump system can block the flow of the refrigerant into the cabin in case of leakage, it is necessary to evaluate the risk of ignition in the underhood of the vehicle for safer operation. Therefore, we established a model to analyze the safety of R290 leakage of secondary-loop heat pump system for an electric vehicle, and investigated the effect of various driving conditions and leakage situations on the risk.

정부출연연구소 연구인력의 직무특성이 조직몰입에 미치는 영향 연구

이승연(Seungyeon Lee),박수경(Soo-Kyung Park) 한국기술혁신학회 2018 기술혁신학회지 Vol.21 No.3

본 논문은 정부출연연구소 연구인력의 직무특성과 조직몰입과의 관계에서 조직공정성의 매개효과를 알아보고자 하는데 목적을 두고 있다. 이를 위해 국가과학기술연구회 소속 정부출연연구소 25곳에 근무하는 연구직 362명을 대상으로 설문조사를 실시하여, 이들 관계를 알아보기 위한 다중회귀분석을 시행하였다. 그 결과, 자율성과 피드백 직무특성이 조직몰입에 정(+)의 영향을 나타내었으며 직무특성 중 자율성만이 조직공정성의 매개효과를 갖는 것으로 나타났다. 본 연구는 기존 연구에서 거의 다루지 않았던 정부출연연구소의 연구인력을 대상으로 직무특성을 발견하고 조직공정성과 조직몰입의 관계에 대한 매개효과를 실증분석한 점에서 의의를 찾을 수 있다. The aim of this study lies on verifying the mediation effect of organizational justice in the relationship between R&D personnel’s job characteristics and organizational performance within their Government-sponsored research institute. For this, a survey was conducted on 362 R&D personnel members from 25 state-sponsored research institutes under National Research Council of Science & Technology, and then, a multiple regression analysis was used to seek any possible relationship. As a result, job characteristics such as autonomy and feedback were found to have positive (+) influence on organizational commitment. In addition, the result of the mediation effect of organizational justice indicated that the impact was made only by autonomy. This study finds its significance in the fact that it revealed the relationship between job characteristics and job satisfaction among R&D personnel in state-sponsored research institutes who have rarely been the source of objectives in related studies, and that it revealed organizational justice mediated the relationship.

편심하중을 받는 탈착식 스퍼드캔의 링플레이트 보강 효과

이승연(Lee, Seungyeon),유일환(You, Ilhwan),박종섭(Park, Jongsup),지광습(Zi, Goangseup) 한국방재학회 2021 한국방재학회논문집 Vol.21 No.5

탈착식 스퍼드캔은 지반의 조건과 관계없이 잭업바지선의 운용을 가능하게 한다. 일반적으로 탈착식 스퍼드캔은 핀을 활용하여 분리된 푸팅과 레그를 연결한다. 하지만 이러한 구조에서는 핀에 과도한 응력이 유발될 수 있다. 본 연구에서는 이러한 탈착식 스퍼드캔의 구조를 개선하기 위해 스퍼드 캔 상부 및 하부에 링플레이트(상⋅하부링)를 보강하는 안을 제시하였다. 유한요소해석 검증 결과, 하부링 및 상부링 보강안에 의해 연결부분의 응력집중이 완화되었으며, 특히 상⋅하부링은 편심 지지조건에서 더욱 큰 효과가 나타났다. 보강 효과를 검증하기 위해 진행된 모형실험 결과, 상⋅하부링 지지구조의 최대 지지 하중은 하부링 지지구조 대비 120%로 나타났다. 본 연구에서 검증한 보강안을 통해 탈착식 스퍼드캔 설계시 연결부의 안전성을 확보할 수 있을 것으로 판단된다. A detachable spudcan enables the operation of a jackup barge on any seabed. A general detachable spudcan uses a pin to connect the separate footing and leg. However, this type of structure can cause excessive stress on the pin. In this study, a new type of detachable spudcan reinforced with ring plates (upper and lower) is proposed to improve the structural performance of the conventional detachable spudcan. Finite element analysis revealed that the stress concentration in the connection part was relieved by reinforcing the lower and upper rings. In particular, reinforcing both lower and upper rings resulted in superior structural performance under eccentric supported conditions than when reinforcing only the lower ring. The structural strength of the spudcan when both the upper and lower rings were reinforced was found to be 120% of the spudcan as compared to when only the lower ring was reinforced. It is thought that the safety of the connection part can be secured when designing a detachable spudcan using the reinforcement plan verified in this study.

고온기 토마토 재배 시 측지 방임을 통한 생육 균형 조절

이승연(Seungyeon Lee),이문행(Munhaeng Lee),이희경(Heekyoung Lee),김경제(Kyoungje Kim) 한국원예학회 2022 한국원예학회 학술발표요지 Vol.2022 No.11

왕복형 자기냉동시스템 내 양방향 유동 구간의 영향 분석

이승연(Seungyeon Lee),최종민(Jongmin Choi),김민수(Min Soo Kim) 대한설비공학회 2022 대한설비공학회 학술발표대회논문집 Vol.2022 No.6

In this study, we have developed a reciprocating magnetic refrigeration system and analyzed the effect of the bi-directional flow region in the system. This system consists of four active magnetic regenerators(AMRs), and each of them contains around 15.1 g of 1.0~1.4 mm gadolinium chips with 60.4 g in total in the system. Four AMRs can be groups as two according to the magnetization state and two AMRs in each group are connected in series. In the connection region, bi-directional flow occurs due to the direction change of the heat transfer fluid flow according to the magnetization state change. In the experiments, we modified the structure of this region and compared the temperatures of each end of AMRs and the temperature spans, that present the system performance. As the results, we observed that we can reduce the temperature difference occurred at the bi-directional region to 0.1 ℃, which was 2 ℃ in the original system, and also increase the maximum temperature span from 5.8 ℃ to 7.2 ℃ .

포스트 Z세대를 위한 미래 교육평가의 방향

이승연(Seungyeon Lee),정영현(Younghyun Jung),이정연(Jeong Youn Lee) 학습자중심교과교육학회 2021 학습자중심교과교육연구 Vol.21 No.20

목적 이 연구는 새롭게 등장하는 알파세대(2010년 이후 출생)로의 세대 전환의 경계에 있는 Z세대의 세대 특성과 교육 평가에 관한 학생 및 교사의 경험을 탐구하고, 미래 세대의 교육평가 변화 방향성에 대한 시사점을 도출하고자 한다. 방법 이 연구는 설명적 순차 설계를 통한 혼합연구방법을 활용해 연구를 수행하였다. 먼저 알파세대 및 Z세대에 대한 문헌검토, 사전설문, 전문가 의견 검토 등을 통해 개발한 설문조사를 통해 교사 81명과 학생 197명의 응답을 분석한 후, 도출된 연구결과의 해석을 보완하기 위해 교사 4명과 학생 9명을 대상으로 반구조화 면담을 수행하였다. 연구진은 양적 및 질적 자료에 기반한 토의 및 통합적 해석을 통해 결론을 도출하였다. 결과 연구 결과 포스트 Z세대는 크게 다섯 가지의 세대 특징을 공유하고 있는 한편, 교사와 학생 간에 해석의 차이가 있는 것으로 나타났다. 또한, 선호하는 평가의 과정도 교사와 학생 간에 대체로 차이가 있었다. 결론 이와 같이 교사와 학생들의 인식 차이를 중심으로 분석한 미래세대의 교육평가 방안은 다섯 가지로 정리되었다. 특히 미래세대의 교육평가에 대한 최근의 다양한 시도와 방안이 현장에서 어떠한 요인 때문에 실천에 어려움이 있는지를 탐구함으로써 이를 개선할 수 있는 방향을 제시하고자 한다. Objectives This research explored the features of Post-generation Z - which is the generation cohort that belongs in the borders of change to the new Generation Alpha (generation cohort born after 2010) - and compared the perception that students and teachers have regarding their experience with the Generation. This research aims to bring out implications to how school assessment could change for the following generation. Methods The research was conducted through a sequential explanatory design research model. First, a survey on school assessment for Post-generation Z was designed by reviewing previous research, pre-surveys, and expert group reviews. Response of 81 teachers and 197 students were analyzed, and interviews of four teachers and nine students were analyzed to supplement the comprehension of results from the survey. The researchers reached the conclusion through discussion on the thorough interpretation of the overall responses. Results There were five main characteristics to Post-generation Z, but the interpretation of teachers and students had some differences. Also, their perception of the factors of assessment was found to have differences. Conclusions According to the results, the research provides five main implications to where school assessment for future generations should head. Especially, this research focus on why current attempts at school assessment reform have encountered difficulties on-site and how they could be solved.