고진동수 계단의 진동응답 산정을 위한 등가임펄스 산정식 제안

김나은,이철호,김성용,Kim, Na Eun,Lee, Cheol Ho,Kim, Sung Yong 한국강구조학회 2015 한국강구조학회 논문집 Vol.27 No.2

심미성과 기능성이 현대 건축의 중요한 요소로 대두되면서 최근 비교적 경량의 고진동수 계단의 활용처가 점차 증가하고 있다. 하지만 국내의 실정 상 고진동수 계단의 진동성능을 평가하기 위한 방법이 전무한 실정이다. 유럽강구조학회의 지침의 경우 등가임펄스하중 개념을 도입하여 고진동수 바닥의 응답예측 및 진동성능 평가에 활용하고 있으나, 이는 서행보행에 대한 실험치를 토대로 제안한 값으로 2.2Hz 이상의 속보 가진에 대한 응답을 과대평가하는 한계를 지니고 있다. 이에 본 연구에는 1.4~4.5Hz의 다양한 가진진동수에 대한 가속도 응답의 실측값을 바탕으로 서행 및 속보 가진 시의 응답을 합리적으로 예측할 수 있는 등가임펄스 식을 제안하였다. High-frequency staircases are widely used nowadays to meet aesthetics and functionality needed in modern architecture. Unfortunately, no design guide is available in domestic practice to predict response or evaluate the vibration performance of high-frequency staircases. SCI-P354 published by the Steel Construction Institute of UK provides the formula for effective impulsive force. However, this formula was shown to overestimate the response of high-frequency staircases excited by fast ascending and descending over 2.2Hz pace frequency because it was developed based on the walking test in a slow pace frequency. This study proposes a semi-analytical formula to predict the response of stiff staircases based on analytical and experimental studies of response acceleration for various walking frequencies covering 1.4~4.5Hz.

비생물적 스트레스 환경에서 Enterobacter ludwigii SJR3 처리 시 토마토의 생장과 스트레스-관련 유전자의 발현

김나은,송홍규,Kim, Na-Eun,Song, Hong-Gyu 한국미생물학회 2016 미생물학회지 Vol.52 No.2

This study examined effects of Enterobacter ludwigii SJR3 showing a high 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, on growth of tomato plant and its expression of stress-related genes under drought and salt stress. SJR3 strain was inoculated at $10^6cell/g$ soil to 4-week grown tomato plants, and drought and salt stresses were treated. After additional incubation for 1 week, root length, stem length, fresh weight and dry weight of tomato plants treated with SJR3 increased by 37.8, 37.2, 96.8 and 146.6%, respectively compared to those of uninoculated plants in drought stress environment, and they increased by 19.2, 25.4, 19.5, and 105.8%, respectively in salt stress environment. Proline content in tomato leaves increased significantly under stress conditions as one of a protecting substance against stresses, but proline contents in tomato treated with SJR3 decreased by 62.1 and 54.1%, respectively. Relative expression of genes encoding ACC oxidase, ACO1 and ACO4, ethylene response factor genes ERF1 and ERF4, and some other stress-related genes were examined from tomato leaves. Compared to the non-stressed tomato, expressions of all stress-related genes increased significantly in the stressed tomato, but gene expressions in the inoculated tomato were similar to those of no-stressed control tomato. Therefore, E. ludwigii SJR3 may play an important role in mitigating drought and salt stress in plants, and can increase productivity of crops under various abiotic stresses.

구체축열을 위한 이방향 중공슬래브에서 배관방향에 따른 구조거동 평가

김나은(Kim, Na-Eun),주은희(Joo, Eun-Hee),김상모(Kim, Sang-Mo),임재한(Lim, Jae-Han),김희선(Kim, Hee-Sun) 대한건축학회 2013 대한건축학회 학술발표대회 논문집 Vol.33 No.2

존 파우슨(John Pawson)의 가구 디자인 특성 연구

김나은(Kim, Na-Eun),박종구(Park, Chong-Ku),이정욱(Lee, Jung-Wook) 한국실내디자인학회 2014 한국실내디자인학회논문집 Vol.23 No.3

Furniture has been developed in pursuit of human convenience and comfort, but nowadays it does not consider human users and gradually loses the essence of furniture. Especially furniture design that disregards the relation with space loses both the meaning and purpose of furniture. In this regards, it is necessary to understand the essence of furniture design and establish a design direction for future progress. Based on the relation between furniture and space, this paper intended to study on John Pawson’s works that pursued the essence of design focusing on users, and propose a direction in a sense of real meaning for modern furniture design after exploring the characteristic of the furniture design of John Pawson. The study method of this paper was to investigate the design language of John Pawson and analyze his furniture in the morphological · structural, functional, and material aspects. Based on such analysis, this study investigated the characteristics of the furniture design and found out what the core of the design that he pursued was. The scope of the study included the Independent Furniture that was restricted furniture collections of Driade and Spatial Furniture designed and installed at the stage of space construction. The study result showed that the design of John Pawson considered ‘the suitability to a specific place’ as important factor and furniture was planned at the stage of planning space. Each independent furniture defines all spaces in the morphological, lay-out and functional aspects of furniture and emphasizes their own property. As Spatial Furniture shares the function of spatial composition element, Pawson’ s furniture can be all called Spatial Furniture.

AI 기반 질의응답 시스템을 통한 우주 시스템 개발 정보의 지능적 활용 방안

김나은(Na Eun Kim),손성은(Seong Eun Son),김진일(Jin Il Kim) 한국항공우주학회 2023 한국항공우주학회 학술발표회 논문집 Vol.2023 No.6

온라인 관광 구전정보품질이 구전효과에 미치는 영향

김나은(Na Eun Kim),김민화(Min Hwa Kim) 한국호텔외식관광경영학회 2010 호텔경영학연구 Vol.19 No.4

The Internet has established itself as the most powerful grassroots channel in every field of information search, which is no exception for the tourism scene. While in the past commercial travel agencies, industry experts, or specialized magazines and books were among the primary sources for travelling information, today the use of the Internet has allowed one to look for and collect information from more various references. Further, travellers themselves, as active providers as well as users, are able to more effectively and freely acquire, express, and exchange useful information and opinions through various channels online. In general, word-of-mouth information is more influential because of its high reliability as the pure one without commercial intentions compared to other information source. Moreover, in the case of tourism products, with the difficulty involving in verification of their reliability as well as their characteristic of having higher perceived risk, they are shown to have relatively heavier reliance on word-of-mouth information. In the online contexts where facial contacts lack between information senders and receivers, rather than their personal information, characteristics of the word-of-mouth message itself are in place as more important criterion for assessment of information value. Drawing from previous literature, this research derived consensus, vividness, accuracy, timeliness, and playfulness as online tourism word-of-mouth characteristics, thereby exploring how they influence word-of-mouth effects via credibility and usefulness. The findings revealed that the four word-of mouth characteristics, except for consensus, had positive impact on credibility and usefulness, which in turn significantly affected word-of-mouth effects.

지방공무원 수당 부당수령의 영향요인에 관한 연구: A 광역시 사례

김나은(Kim, Na-Eun),정혜진(Jung, Hye-Jin) 한국정부학회 2020 한국행정논집 Vol.32 No.3

수당이 보수에서 차지하는 비중은 줄어들었지만, 지급기준과 목적이 명확히 정해지지 않은 수당들이 보수의 투명성을 떨어뜨리고 보수체계의 왜곡을 초래하고 있다. 이에 본 연구는 A 광역시에서 호봉제 적용을 받는 6급 이하의 일반직 공무원을 대상으로 공무원 수당 부당수령에 영향을 미치는 요인들을 실증적으로 조사하고자 한다. 부패 삼각이론 및 선행연구를 바탕으로 공무원 수당 부당수령에 영향을 미치는 독립변수로서 보수 만족도, 보수 공정성, 제도, 조직 문화를 선정하였다. 153명의 응답을 토대로 로짓 분석을 수행한 결과 타인의 부당수령 목격 경험 및 자신의 부당수령 경험에 영향을 미치는 요인이 다르게 분석되었다. 타인의 부당수령 목격 경험에 영향을 미치는 요인은 조직 문화만 유의하게 도출된 반면, 자신의 부당수령 경험은 보수 공정성과 조직 문화가 유의한 영향을 미치는 것으로 나타났다. 통제변수 중 직급은 타인의 부당수령 목격 경험 및 자신의 부당수령 경험 모두에 유의한 영향을 미쳤다. 통계 분석과 더불어 일부 응답자들을 대상으로 익명 인터뷰를 수행하여 이를 토대로 공무원의 수당 부당수령을 낮출 수 있는 정책적 시사점을 제시하였다. Though the portion of allowance has decreased over the years, there are still obscure criteria and purposes of allowance for public employees that can lead to a distortion of pay system. The purpose of present study is to explore influencing factors of receiving illegal allowance among Level 6 or less public employees working at A metropolitan city. Based on fraud triangle theory and relevant literature, we employed a number of independent variables including salary satisfaction, salary fairness, institution, and organizational culture. We conducted a logistic analysis using a total of 153 survey questionnaires. The results indicated that the factors varied by the dependent variables: While organizational culture is a sole contributing factor for observation of illegal receipt of colleagues, both organizational culture and salary fairness were significant factors for their own experiences of illegal receipt. Among the control variables, the position of public employees had statistically significant relationships with both dependent variables. We also interpreted the statistical results with in-depth interview conversations to draw policy implications that can impede the problems of receiving illegal allowance among public employees.

3차원 형상설계를 이용한 UAM 버티포트 구조해석에 관한 연구

김나은(Kim, Na Eun),정유빈(Jeong Yu Bin),김민지(Kim, Min Ji),정제평(Jeong, Je Pyong) 대한토목학회 2021 대한토목학회 학술대회 Vol.2021 No.10

온실 내 환경데이터 분석을 통한 파프리카 온실의 식별

김나은(Na-eun Kim),이경근(Kyoung-geun Lee),이덕현(Deog-hyun Lee),문병은(Byeong-eun Moon),박재성(Jae-sung Park),김현태(Hyeon-tae Kim) (사)한국생물환경조절학회 2021 생물환경조절학회지 Vol.30 No.1

머신러닝 알고리즘을 이용한 온실 딸기 생산량 예측

김나은(Na-eun Kim),한희선(Hee-sun Han),아룰모지엘렌체쟌(Elanchezhian Arulmozhi),문병은(Byeong-eun Moon),최영우(Yung-Woo Choi),김현태(Hyeon-tae Kim) (사)한국생물환경조절학회 2022 생물환경조절학회지 Vol.31 No.1

서부 경남 지역 중 딸기재배로 유명한 지역 40개 농가를 대상으로 한 조사에 따르면 국산품종 중에서 “설향”이 65.0%으로서 가장 선호하고 있는 것으로 나타났다. 그리고 현재의 농업은 4차 산업혁명으로 스마트팜(Smart Farm)의 기술이 더욱 발전하고 있는 실정이다. 그러나 각 생육단계가 어떤 상황일 때 딸기의 생산량이 최적에 달하는지 대한 기준이 없으며, 이러한 판단기준은 아직까지 스마트팜에 경험이 있는 농업인의 의사에 달려있다는 문제점이 있다. 따라서 본 연구에서는 딸기의 생육상황에 대한 생산량 예측을 통해 선진화된 스마트팜 시스템을 구축하고자 한다. 실험 장소는 경상남도 사천시의 딸기 농가에서 수행하였으며, 총 3곳을 대상으로 데이터 수집을 진행하였다. 실험 대상의 모든 온실 내에서 재배하는 딸기의 품종은 ‘설향’이다. 작물 데이터의 수집 항목은 작물의 엽수, 꽃수, 과실수, 초장, 잎의 길이, 엽록소 함량이며, 환경 데이터의 수집 항목은 온도, 습도, 조도이다. 기존의 농가 단위의 스마트팜의 문제점 보완 및 개선을 통하여 고품질의 작물 생장 상태를 유지하기 위해 K-fold 교차검증, Lasso 회귀분석, MAPE 검증을 통해 예측모델을 도출하였으며, MAPE 검증결과 값으로 0.511(꽃 예측)과 0.488(과일 예측)의 값이 나타났다. 본 연구는 스마트팜 데이터 구축을 위해서는 AI를 통해 성장상태별 수확량을 예측하였으며, 이를 농가 및 농업 관련기업에 활용해 농업 서비스가 편리할 것으로 판단된다. Strawberry is a stand-out cultivating fruit in Korea. The optimum production of strawberry is highly dependent on growing environment. Smart farm technology, and automatic monitoring and control system maintain a favorable environment for strawberry growth in greenhouses, as well as play an important role to improve production. Moreover, physiological parameters of strawberry plant and it is surrounding environment may allow to give an idea on production of strawberry. Therefore, this study intends to build a machine learning model to predict strawberry’s yield, cultivated in greenhouse. The environmental parameter like as temperature, humidity and CO₂ and physiological parameters such as length of leaves, number of flowers and fruits and chlorophyll content of ‘Seolhyang’ (widely growing strawberry cultivar in Korea) were collected from three strawberry greenhouses located in Sacheon of Gyeongsangnam-do during the period of 2019-2020. A predictive model, Lasso regression was designed and validated through 5-fold cross-validation. The current study found that performance of the Lasso regression model is good to predict the number of flowers and fruits, when the MAPE value are 0.511 and 0.488, respectively during the model validation. Overall, the present study demonstrates that using AI based regression model may be convenient for farms and agricultural companies to predict yield of crops with fewer input attributes.